Today's puzzle is a Skyscraper Sudoku variant. This is a more Logic Puzzle variant of Sudoku. I normally would represent this as a Regional variant of Skyscraper puzzles. The Sudoku part doesn't often come forward as much as the Skyscraper part during the solve. But as I always like Skyscraper Sudokus, I figured I'd make one too. This variant sometimes has all possible arrows given, but I prefer it without this rule. A lot of the smaller numbers end up being unnecessarily given an arrow there, although the negative information is also fun to use. I just prefer it this way.

I had set up this opening a few weeks ago, but I was not able to finish the puzzle successfully. After a few more tries, I came up with this puzzle. I was originally intending to make the clue arrangement symmetric, but as you can't just put a clue everywhere that caused some problems. This was the point where the puzzle ended up being unique. I liked the way it solved at the end, with a somewhat tricky step to finish the puzzle. So that's why I settled for this one. I had a little trouble finding a satisfying layout, but I think this one should do. If someone has a suggestion that could work better, I might change the image. Having said that, enjoy the puzzle.

Rules for Sudoku

In this Sudoku each digit indicates the height of a Skyscraper. Digits in cells with arrows indicate the number of buildings that can be seen in the direction of the arrow from that cell. Taller buildings block the view of smaller buildings.

## Saturday 28 December 2013

## Saturday 21 December 2013

### Daily League Sudoku #39: Palindrome Killer Sudoku

Today's Sudoku is themed around today's date. As the date is a palindrome, the choice of Sudoku was easy. I chose for the combination with Killer Sudoku as I could use 21 and 12 easily in that variant.

The puzzle has a somewhat complicated opening. But I hope that people will understand where to look considering the choice of combined variants. If not, I guess there's very little to get in this one. But when the opening's finished, the solve should solve without much problems.I'm still happy with the Sudoku overall. I think the 21/12 layout of cages looks really nice and the way the palindrome resolves the obvious non-uniqueness worked out really well. I hope people will feel the same. Enjoy.

The puzzle has a somewhat complicated opening. But I hope that people will understand where to look considering the choice of combined variants. If not, I guess there's very little to get in this one. But when the opening's finished, the solve should solve without much problems.I'm still happy with the Sudoku overall. I think the 21/12 layout of cages looks really nice and the way the palindrome resolves the obvious non-uniqueness worked out really well. I hope people will feel the same. Enjoy.

Instead of given numbers, you now have a few dashed cages. The number in a cage indicates the sum of the digits in the cage. Digits can't be repeated in any dashed cage. Additionally, digits along a grey line must form a palindromic sequence.

Click to enlarge |

## Sunday 15 December 2013

### Daily League Sudoku #38: Parity Count Sudoku

This week's Sudoku is an Odd/Even Sudoku variant. I'm pretty sure I have seen this idea before. I have no idea where or what is was called then. So I just gave it my own name.

I always like Sudokus that use parity constraints, which require you to basically build an Odd/Even Sudoku. I made a puzzle that required this before, namely my Battenburg Sudoku. In this one you actually have to solve the Sudoku to set up the whole Odd/Even Sudoku grid. I think because of the interaction between Sudoku and parity rule, this idea is a bit more interesting. I don't think the puzzle is overly difficult. The opening shouldn't be too hard, but there's a few sticking points in the middle in figuring out which numbers go in certain grey cells. I had fun designing it. I sacrificed symmetry a bit as the left top square being grey helped make it unique and I preferred that over giving extra givens. I hope people enjoy it.

Rules for Sudoku

In this Sudoku digits in grey cells indicate how many digits of the opposite parity appear in the cells touching it.

I always like Sudokus that use parity constraints, which require you to basically build an Odd/Even Sudoku. I made a puzzle that required this before, namely my Battenburg Sudoku. In this one you actually have to solve the Sudoku to set up the whole Odd/Even Sudoku grid. I think because of the interaction between Sudoku and parity rule, this idea is a bit more interesting. I don't think the puzzle is overly difficult. The opening shouldn't be too hard, but there's a few sticking points in the middle in figuring out which numbers go in certain grey cells. I had fun designing it. I sacrificed symmetry a bit as the left top square being grey helped make it unique and I preferred that over giving extra givens. I hope people enjoy it.

Rules for Sudoku

In this Sudoku digits in grey cells indicate how many digits of the opposite parity appear in the cells touching it.

## Saturday 7 December 2013

### Daily League Sudoku #37: Non-Consecutive Sudoku

This week again something familiar. I had a different puzzle ready, but I sadly realised my intended opening made no sense. I had adjusted two digits, which I thought didn't affect the opening, but on a resolve I realised they did. I will give that one another go later, but I didn't really have the time to fix it today. So instead here is a Non-Consecutive Sudoku.

I always enjoy solving Non-Consecutive Sudokus. I think writing them is a lot trickier though. I think it doesn't really suit the way I like to write Sudokus or puzzles in general. I think the puzzle solves nicely, but it won't be one of my more memorable Sudokus. But as I promised a more easy Sudoku this week, I think this one will at least keep that promise. Enjoy :).

Rules for Sudoku

In this Sudoku consecutive digits can't be orthogonally adjacent.

I always enjoy solving Non-Consecutive Sudokus. I think writing them is a lot trickier though. I think it doesn't really suit the way I like to write Sudokus or puzzles in general. I think the puzzle solves nicely, but it won't be one of my more memorable Sudokus. But as I promised a more easy Sudoku this week, I think this one will at least keep that promise. Enjoy :).

Rules for Sudoku

In this Sudoku consecutive digits can't be orthogonally adjacent.

## Saturday 30 November 2013

### Daily League Sudoku #36: Sum Relations Sudoku

I have seen puzzles similar to this before, except in a Killer Sudoku format. In those puzzles the relations are given between different cages. Here the relation is between the sums of adjacent cells on either side of the symbol.

This is again a harder puzzle. I don't know exactly how hard it is, but there's definitely no progress to be made if you don't understand the opening. I wasn't expecting to be able to make this variant without any givens. But I managed to create an opening that works without any givens. I think it's a nice and interesting opening. The middle is probably a bit easier, but I think the end is again a little bit harder, but worked out nicely in my opinion. I'll think about making something easier again next week, but I can't exactly promise that. When I find an interesting opening, I just run with it. And interesting is generally hard. Enjoy this puzzle though.

This is again a harder puzzle. I don't know exactly how hard it is, but there's definitely no progress to be made if you don't understand the opening. I wasn't expecting to be able to make this variant without any givens. But I managed to create an opening that works without any givens. I think it's a nice and interesting opening. The middle is probably a bit easier, but I think the end is again a little bit harder, but worked out nicely in my opinion. I'll think about making something easier again next week, but I can't exactly promise that. When I find an interesting opening, I just run with it. And interesting is generally hard. Enjoy this puzzle though.

In this Sudoku, the symbols indicate the relation between the sums of the 2 cells on either side of the symbol.

## Saturday 23 November 2013

### Daily League Sudoku #35: Rank Killer Sudoku

This week a puzzle type taken from Richard Stolk's V2V test at Logicmasters India. I had planned on posting this type earlier, but my attempts at making one never got anything useful. So I made other puzzle types instead, that worked out easier. But this one seemed to work well.

This puzzle is again a harder one. I had posted a few easier ones in the last few weeks. This type has again some room for me to be a bit more creative with the opening. There's a few steps that combine Killer Sudoku and Rank Sudoku to start this one off. They are still all logical steps, but it takes a bit more effort to figure them out. I still think it is an enjoyable puzzle.

As a reminder all Daily League puzzles are also solvable at SudokuCup.

Rules for Sudoku

The sum of digits inside each dashed cage is given at the upper left cell of the cage. A digit 'N' in a circle means that the digit in the cell is the Nth smallest number in the corresponding cage. Digits cannot repeat within a cage.

This puzzle is again a harder one. I had posted a few easier ones in the last few weeks. This type has again some room for me to be a bit more creative with the opening. There's a few steps that combine Killer Sudoku and Rank Sudoku to start this one off. They are still all logical steps, but it takes a bit more effort to figure them out. I still think it is an enjoyable puzzle.

As a reminder all Daily League puzzles are also solvable at SudokuCup.

Rules for Sudoku

The sum of digits inside each dashed cage is given at the upper left cell of the cage. A digit 'N' in a circle means that the digit in the cell is the Nth smallest number in the corresponding cage. Digits cannot repeat within a cage.

Click to enlarge |

## Saturday 16 November 2013

### Daily League #34: Arrow Sudoku

This week a more familiar variant. Arrow Sudoku has been around for a while now and there's been many nice puzzles made. I hope this one is also enjoyable.

I decided to go for a similar layout as my Renban Sudoku I made a while back for the league. I thought it would work well with Arrow Sudoku too. I was able to give fewer givens though as the arrow already forces some placement because of the direction. I shortly considered making a directionless Arrow Sudoku, where the circle could be at either end, but this layout wasn't very friendly for that variant. At first I had a harder variant of this Sudoku, but it took me too long to solve it myself while knowing the openings because the middle and end ran a lot on very complex interactions between the arrows that I really couldn't justify logically. So I revamped it a little to make it more solvable. The harder opening is still in this puzzle but it is no longer needed to solve the puzzle as there's a more friendly path through the puzzle.

Rules for Sudoku

In this Sudoku a number of arrows are given with a circle at the end. The digit in a circle is equal to the sum of the digits along its arrow. Digits may repeat along an arrow as long as they don't break any Sudoku rules.

I decided to go for a similar layout as my Renban Sudoku I made a while back for the league. I thought it would work well with Arrow Sudoku too. I was able to give fewer givens though as the arrow already forces some placement because of the direction. I shortly considered making a directionless Arrow Sudoku, where the circle could be at either end, but this layout wasn't very friendly for that variant. At first I had a harder variant of this Sudoku, but it took me too long to solve it myself while knowing the openings because the middle and end ran a lot on very complex interactions between the arrows that I really couldn't justify logically. So I revamped it a little to make it more solvable. The harder opening is still in this puzzle but it is no longer needed to solve the puzzle as there's a more friendly path through the puzzle.

Rules for Sudoku

In this Sudoku a number of arrows are given with a circle at the end. The digit in a circle is equal to the sum of the digits along its arrow. Digits may repeat along an arrow as long as they don't break any Sudoku rules.

## Saturday 9 November 2013

### Daily League Sudoku #33: Hi-Lo Product Frame Sudoku

This week another variation on the Hi-Lo Frame Sudoku. It's a fun variant you can always play around with. This time it's products instead of sums. It leaves for fewer options and thus allows fewer clues.

Outside clues and empty grids are always my favourite Sudokus to construct. It's generally a bit of a struggle to get them to turn out unique or even create an opening. This one was a bit of a struggle to get unique as my final clue had to settle about 35 cells. There were a few options that got pretty close but would end up having no solution. This was the only one I could find that settled the uniqueness issue. There was a second option that I thought had worked, but then I realised the clue didn't actually have to be in that configuration and thus there were many more solutions. The puzzle itself is not overly hard as the clues give you a lot of information from the start and the clue I used for uniqueness is already helpful far earlier than it was in my construction.

Rules for Sudoku

In this Sudoku, the numbers on the outside indicate the product of the highest and lowest digit in the first three cells of that row or column when looking from that side.

Outside clues and empty grids are always my favourite Sudokus to construct. It's generally a bit of a struggle to get them to turn out unique or even create an opening. This one was a bit of a struggle to get unique as my final clue had to settle about 35 cells. There were a few options that got pretty close but would end up having no solution. This was the only one I could find that settled the uniqueness issue. There was a second option that I thought had worked, but then I realised the clue didn't actually have to be in that configuration and thus there were many more solutions. The puzzle itself is not overly hard as the clues give you a lot of information from the start and the clue I used for uniqueness is already helpful far earlier than it was in my construction.

Rules for Sudoku

In this Sudoku, the numbers on the outside indicate the product of the highest and lowest digit in the first three cells of that row or column when looking from that side.

### Daily League Sudoku #32: N-Sums Sudoku and Quad Max Difference Sudoku

This post is just preceding this week's Sudoku. I hadn't made blogposts of my previous 2 Sudoku. The first one was made en route to Beijing for the WSC/WPC. I had no access to Facebook or BlogSpot there, so I wasn't able to make any posts. The second one I was not at home and managed to sneak in some time to make a quick Facebook post with the image, which all is a little bit faster than making posts on my blog.

The first puzzle is a variant on the X-Sums Sudoku, of which I have made a few. The variant is a bit more limiting as now not every row and column necessarily has a valid clue. This is caused by the fact that a number N has to appear in position N to become a valid clue. The construction took a while as I wanted to keep the symmetric layout and sometimes I wasn't able to make the layout symmetric as there was no longer a clue available. There are a few clues that aren't necessary for uniqueness in this puzzle, but they don't hinder the solving path and make it overall a little bit easier. I think people don't mind that my Sudokus are made a bit easier in general.

The second puzzle is a simple variant with differences. It has more given numbers than I would have wanted, but it wouldn't be unique otherwise. I wanted to make a puzzle which had a single instance of every possible Quad Difference clue possible. This of course forced one of the clues to be in a specific position as otherwise there's be no unique solution available. Which is why I went for this layout. I don't think this one is overly hard. There's a few key points in the solve where you have to use the right clues.

Rules for Sudoku

Clues outside the grid indicate the sum of the first N digits seen in that row or column from that side. The digit N is always indicated by the Nth digit seen from that side. In other words, it is always the last digit in the summed set of digits.

In this Sudoku, numbers on grid points indicate the maximum difference between the four digits surrounding it. Each difference must appear at least once around each clue.

The first puzzle is a variant on the X-Sums Sudoku, of which I have made a few. The variant is a bit more limiting as now not every row and column necessarily has a valid clue. This is caused by the fact that a number N has to appear in position N to become a valid clue. The construction took a while as I wanted to keep the symmetric layout and sometimes I wasn't able to make the layout symmetric as there was no longer a clue available. There are a few clues that aren't necessary for uniqueness in this puzzle, but they don't hinder the solving path and make it overall a little bit easier. I think people don't mind that my Sudokus are made a bit easier in general.

The second puzzle is a simple variant with differences. It has more given numbers than I would have wanted, but it wouldn't be unique otherwise. I wanted to make a puzzle which had a single instance of every possible Quad Difference clue possible. This of course forced one of the clues to be in a specific position as otherwise there's be no unique solution available. Which is why I went for this layout. I don't think this one is overly hard. There's a few key points in the solve where you have to use the right clues.

Rules for Sudoku

**N-Sums Sudoku:**Clues outside the grid indicate the sum of the first N digits seen in that row or column from that side. The digit N is always indicated by the Nth digit seen from that side. In other words, it is always the last digit in the summed set of digits.

**Quad Max Difference Sudoku:**In this Sudoku, numbers on grid points indicate the maximum difference between the four digits surrounding it. Each difference must appear at least once around each clue.

## Saturday 5 October 2013

### Daily League Sudoku #31: WSC Jigsaw Sudoku

The post is coming from Las Vegas this time. I made this puzzle poolside relaxing in the sun after making my way to part of the WSC instruction booklet. The example in the booklet of this puzzle isn't that challenging, so I figured I'd give a more instructive one. The logic in placement is solid and the remaining solve shouldn't be very hard. I think this is doable within 15 minutes. I don't have a B or C version.

I hope it's a fun puzzle and maybe some help for the upcoming WSC. See all of you who are going there in a few days.

Recap of the last Daily League week:

Sunday: Product or Outside Sudoku by Seungjae Kwak

Monday: No Ten Sudoku by Jakub Hrazdira

Tuesday: Monopoly Untouch Sudoku by Prasanna Seshadri

Wednesday: Extra Regions Sudoku by Bastien Vial-Jaime

Thursday: Arrow Sudoku by Rishi Puri

Friday: Killer Sudoku by Tom Collyer

Saturday: Odd-Even View Sudoku by Hall Hur

Sunday: Simple Math Variation Sudoku by Seungjae Kwak

Monday: Diagonal Sudoku by Karel Tesar

Tuesday: Consecutive Sudoku by Prasanna Seshadri

Wednesday: Point to Next Sudoku by Bastien Vial-Jaime

Thursday: Pyramid Sudoku by Rishi Puri

Friday: Killer Sudoku by Benz Liang

Daily League PDFs:

Week 37

Rules for Sudoku

In this Sudoku, place the given Jigsaw pieces in the grid and solve the resulting Expanded Sudoku. The pieces can't be rotated or reflected and they can't overlap eachother. In an Expanded Sudoku some of the rows and columns expand over empty space.

I hope it's a fun puzzle and maybe some help for the upcoming WSC. See all of you who are going there in a few days.

Recap of the last Daily League week:

Sunday: Product or Outside Sudoku by Seungjae Kwak

Monday: No Ten Sudoku by Jakub Hrazdira

Tuesday: Monopoly Untouch Sudoku by Prasanna Seshadri

Wednesday: Extra Regions Sudoku by Bastien Vial-Jaime

Thursday: Arrow Sudoku by Rishi Puri

Friday: Killer Sudoku by Tom Collyer

Saturday: Odd-Even View Sudoku by Hall Hur

Sunday: Simple Math Variation Sudoku by Seungjae Kwak

Monday: Diagonal Sudoku by Karel Tesar

Tuesday: Consecutive Sudoku by Prasanna Seshadri

Wednesday: Point to Next Sudoku by Bastien Vial-Jaime

Thursday: Pyramid Sudoku by Rishi Puri

Friday: Killer Sudoku by Benz Liang

Daily League PDFs:

Week 37

Rules for Sudoku

In this Sudoku, place the given Jigsaw pieces in the grid and solve the resulting Expanded Sudoku. The pieces can't be rotated or reflected and they can't overlap eachother. In an Expanded Sudoku some of the rows and columns expand over empty space.

Click to enlarge |

## Thursday 26 September 2013

### TVC XVI Practise

Hello from Vancouver. Currently travelling before the WPC in Beijing. Need to be relaxed when I arrive there. Although maybe adding a small jetlag isn't totally the smartest thing. I was better located in Australia for that.

I wasn't sure if I could post any puzzles this week for the upcoming TVC XVI at Logic Master India.. I wrote a few puzzles on the plane, so I figure I'd share those. I hope they are of some use to people. Hopefully I will be able to compete in the last few days of the CTC and the last TVC. We will see. Everyone have fun at least.

There are four Tapas in this post.

The first puzzle is a Symmetric Tapa. This rule is very influential in the solve, so you really don't need many clues if you place your rectangles smartly. This one has four clues, but really shouldn't be that difficult a solve. I made it 11x11 as that way the rectangles would less likely share an edge if I placed all dots on grid points.

The second puzzle is a Toroidal Tapa. I like this variant. It's a bit trickier to design as you need to set a lot more blocks to make sure you can guide the wall where you want it to. I think this is a genre that can always use some practise, especially with looking around the edges of the grid. This puzzle is 12x12 as I liked this pattern of givens.

The third puzzle is a Transparent Tapa. This is the only genre that hasn't previously appeared on a TVC, so I figured I should at least make one of these. Although people can find a few of them on Prasanna Seshadri's blog. Oddly enough this rule change only means there is one clue that is invalid in normal Tapa. This one is also 12x12. I made an opening and then I noticed it would work more effectively in the corner of the grid. But to make a nice pattern of givens it would be better for the grid to be 12x12.

The fourth puzzle is a Alternative Tapa. This is the hardest of the four puzzles. This is not caused by the variant, as it's not overly influential in the solve. But the normal Tapa bit is pretty challenging and should give you all a bit of a challenge. Although maybe with the CTC you've had enough of those already. This one is 11x11 as it worked nicely with the TVC XVI pattern of letters.

Enjoy and have fun this weekend.

Puzzle can be found below.

I wasn't sure if I could post any puzzles this week for the upcoming TVC XVI at Logic Master India.. I wrote a few puzzles on the plane, so I figure I'd share those. I hope they are of some use to people. Hopefully I will be able to compete in the last few days of the CTC and the last TVC. We will see. Everyone have fun at least.

There are four Tapas in this post.

The first puzzle is a Symmetric Tapa. This rule is very influential in the solve, so you really don't need many clues if you place your rectangles smartly. This one has four clues, but really shouldn't be that difficult a solve. I made it 11x11 as that way the rectangles would less likely share an edge if I placed all dots on grid points.

The second puzzle is a Toroidal Tapa. I like this variant. It's a bit trickier to design as you need to set a lot more blocks to make sure you can guide the wall where you want it to. I think this is a genre that can always use some practise, especially with looking around the edges of the grid. This puzzle is 12x12 as I liked this pattern of givens.

The third puzzle is a Transparent Tapa. This is the only genre that hasn't previously appeared on a TVC, so I figured I should at least make one of these. Although people can find a few of them on Prasanna Seshadri's blog. Oddly enough this rule change only means there is one clue that is invalid in normal Tapa. This one is also 12x12. I made an opening and then I noticed it would work more effectively in the corner of the grid. But to make a nice pattern of givens it would be better for the grid to be 12x12.

The fourth puzzle is a Alternative Tapa. This is the hardest of the four puzzles. This is not caused by the variant, as it's not overly influential in the solve. But the normal Tapa bit is pretty challenging and should give you all a bit of a challenge. Although maybe with the CTC you've had enough of those already. This one is 11x11 as it worked nicely with the TVC XVI pattern of letters.

Enjoy and have fun this weekend.

Puzzle can be found below.

## Saturday 21 September 2013

### Daily League Sudoku #30: Toroidal X-Sums Sudoku

This week a combination of two variants I like. X-Sums Sudoku is a genre that works really well with Jigsaw Sudoku, so I figured it would just as well work with Toroidal Sudoku. It's a bit tricky though as it's much easier to overlook that a certain digit already appears in a region. The puzzle is probably on the harder side, but I don't think any of the logic is overly hard. It's just tricky to keep track of everything with the Toroidal regions. I did add a few clues that aren't necessary for uniqueness. But there were clues planned there to keep the symmetry, but the puzzle proved to be unqiue without needing to put any there. They don't really ruin any of the logic, just create a few shortcuts.

Recap of the last Daily League week:

Sunday: Just One Cell Sudoku by Seungjae Kwak

Monday: Diagonally Non-Consecutive Sudoku by Karel Tesar

Tuesday: Arrow Sudoku by Prasanna Seshadri

Wednesday: Skyscraper Sudo-Kurve by Bastien Vial-Jaime

Thursday: Even-Odd Skyscraper Sudoku by Rishi Puri

Friday: Thermo Sudoku by Tom Collyer

Rules for Sudoku

In this Sudoku some of the regions wrap around the edge of the grid. Numbers on the outside indicate the sum of the first X digits in that row or column seen from that side. X is always the first digit in that row or column seen from that side.

Recap of the last Daily League week:

Sunday: Just One Cell Sudoku by Seungjae Kwak

Monday: Diagonally Non-Consecutive Sudoku by Karel Tesar

Tuesday: Arrow Sudoku by Prasanna Seshadri

Wednesday: Skyscraper Sudo-Kurve by Bastien Vial-Jaime

Thursday: Even-Odd Skyscraper Sudoku by Rishi Puri

Friday: Thermo Sudoku by Tom Collyer

Rules for Sudoku

In this Sudoku some of the regions wrap around the edge of the grid. Numbers on the outside indicate the sum of the first X digits in that row or column seen from that side. X is always the first digit in that row or column seen from that side.

## Tuesday 17 September 2013

### Czech Team Puzzle Championship

In the weekend of 7-8 September, the Czech Sudoku and Puzzle Teams Championships were held. The championship was held in Brno. The teams competed in a number of team and individual rounds over the weekend. The Sudoku event was won by the team of Michaela Bieliková, Matúš Demiger, Zuzana Hromcová and Jakub Ondroušek. The puzzle event was won by the Hungarian team of Zoltan Horvath, Pal Madarassy, Major Boglár and Zoltan Nemeth. Full results can be found here.

All Sudokus and puzzles of the championship can be found here. I also provided some of the Sudokus and puzzles for that event. This post will contain all my puzzles.

All my puzzles featured in a single round, together with 2 other puzzles. I hadn't written these puzzles to be a complete round and just wrote a number of different puzzles. It was Karel's idea to use them all together. I chose to write a number of common puzzle types, a number of uncommon and a number of variants of common types. So it's a good mix of puzzles to be featured in a single round. They are mostly puzzle types I had written before, so I knew what to do with them. I'm happy how they turned out and think it was a good mix of easy and hard puzzle.

Puzzles can be found below.

All Sudokus and puzzles of the championship can be found here. I also provided some of the Sudokus and puzzles for that event. This post will contain all my puzzles.

All my puzzles featured in a single round, together with 2 other puzzles. I hadn't written these puzzles to be a complete round and just wrote a number of different puzzles. It was Karel's idea to use them all together. I chose to write a number of common puzzle types, a number of uncommon and a number of variants of common types. So it's a good mix of puzzles to be featured in a single round. They are mostly puzzle types I had written before, so I knew what to do with them. I'm happy how they turned out and think it was a good mix of easy and hard puzzle.

Puzzles can be found below.

### Czech Team Sudoku Championship

In the weekend of 7-8 September, the Czech Sudoku and Puzzle Teams Championships were held. The championship was held in Brno. The teams competed in a number of team and individual rounds over the weekend. The Sudoku event was won by the team of Michaela Bieliková, Matúš Demiger, Zuzana Hromcová and Jakub Ondroušek. The puzzle event was won by the Hungarian team of Zoltan Horvath, Pal Madarassy, Major Boglár and Zoltan Nemeth. Full results can be found here.

All Sudokus and puzzles of the championship can be found here. I also provided some of the Sudokus and puzzles for that event. This post will contain all my Sudokus.

This is the first time I actually provided Sudokus to a championship. Before the start of the Daily League I didn't really regularly write Sudokus. I think I'm getting a bit better on judging difficulty. I provided 3 easier and 3 harder puzzles. I also wrote an examples for each puzzle type. Two of the examples were also included in the championship. I think from the point values of the puzzles, my judgements of difficulty were pretty accurate.

Puzzles can be found below.

All Sudokus and puzzles of the championship can be found here. I also provided some of the Sudokus and puzzles for that event. This post will contain all my Sudokus.

This is the first time I actually provided Sudokus to a championship. Before the start of the Daily League I didn't really regularly write Sudokus. I think I'm getting a bit better on judging difficulty. I provided 3 easier and 3 harder puzzles. I also wrote an examples for each puzzle type. Two of the examples were also included in the championship. I think from the point values of the puzzles, my judgements of difficulty were pretty accurate.

Puzzles can be found below.

## Saturday 14 September 2013

### Daily League Sudoku #29: Different Difference Sudoku

I based this of a puzzle I've seen as an Instructionless Sudoku I've seen before. I don't remember where it was. As I remember it, it was a Sudoku, where in each nth nonet all differences n were marked (e.g. in nonet 1 all differences of 1, in nonet 2 all differences of 2). This puzzle has the same concept, that in each nonet all instances of a particular difference are marked. Except the differences aren't ordered and you have to figure out which nonet corresponds to which difference.

I hope the explanations of the rules are clear. If someone has a better way to formulate them, I'd appreciate it.

I think if you understand how the basics work, it shouldn't be too hard a puzzle. I've written better Sudokus and I think it can be done more elegantly. But overall I like how it turned out. I hope people enjoy it.

Recap of the last Daily League week:

Sunday: Anti-Diagonal Sudoku by Seungjae Kwak

Monday: No Point to Nine Sudoku by Jakub Hrazdira

Tuesday: Slot Machine Sudoku by Prasanna Seshadri

Wednesday: Figures Sudoku by Bastien Vial-Jaime

Thursday: Killer Sudoku by Rishi Puri

Friday: Diagonal Sudoku by Tom Collyer

Daily League PDF's:

Week 32

Week 33

Week 34

Rules for Sudoku

In this Sudoku, adjacent cells in a given 3x3 box containing numbers differing by n are marked. Adjacent cells with no marking must not contain numbers differing by n. The value of n is different for all 3x3 boxes. There is no restriction on adjacent cells contained in different 3x3 boxes.

I hope the explanations of the rules are clear. If someone has a better way to formulate them, I'd appreciate it.

I think if you understand how the basics work, it shouldn't be too hard a puzzle. I've written better Sudokus and I think it can be done more elegantly. But overall I like how it turned out. I hope people enjoy it.

Recap of the last Daily League week:

Sunday: Anti-Diagonal Sudoku by Seungjae Kwak

Monday: No Point to Nine Sudoku by Jakub Hrazdira

Tuesday: Slot Machine Sudoku by Prasanna Seshadri

Wednesday: Figures Sudoku by Bastien Vial-Jaime

Thursday: Killer Sudoku by Rishi Puri

Friday: Diagonal Sudoku by Tom Collyer

Daily League PDF's:

Week 32

Week 33

Week 34

Rules for Sudoku

In this Sudoku, adjacent cells in a given 3x3 box containing numbers differing by n are marked. Adjacent cells with no marking must not contain numbers differing by n. The value of n is different for all 3x3 boxes. There is no restriction on adjacent cells contained in different 3x3 boxes.

## Friday 13 September 2013

### TVC XV Practise: Part 3ish

So, I tried today to make puzzles for the remaining three genres of TVC XV, but really nothing useful came out of it. A lot of tried openings, but in the end just a big mess of nothing useful came out of it. I could post something of the messy remnants of what were once good ideas, but I'm going I'm just going to repost the three old puzzles I have already linked in the Introduction. So for those who didn't bother clicking the many links in that post, you can at least get 3 nice puzzles to solve.

I hope everything still helped prepare people for the upcoming weekend. Enjoy and have fun.

Puzzles can be found below.

I hope everything still helped prepare people for the upcoming weekend. Enjoy and have fun.

Puzzles can be found below.

### TVC XV Practise: Part 2

I was debating on whether to finish the other 3 types or posting these already, but figured I might as well post them now. I'm having some trouble designing certain variants. Both Double Back and Twopa are tricky to get right. The Twopa came together when I gave up on making the clue layout symmetric. It was just too much trouble. I will try to post the rest later today. I hope these puzzles are useful though.

The first puzzle is an Outside Tapa. I don't think this one is as nice as Serkan's puzzle from TVC VII but I think it's nice none-the-less. The variant isn't as influential in this puzzle, but has some points that should be important for the solve. But a few of the outside clues are purely to settle uniqueness.

The second puzzle is a Total False Tapa. This variant seems to always require a lot of clues. When I was done with the design I actually went out to edit the puzzle a bit, replacing multiple clues with 8's as the actual value of the clue was unnecessary, meaning that an 8 would work just as well. I think it makes the puzzle a bit nicer a solve. I think the end of the solve it trickiest.

The third Puzzle is a Twopa. It's a really tricky type to design, but I don't think the solve is particularly challenging. The main problem here is that you can't just add clues wherever you want as it might not work for both puzzles or it might not solve differently for both puzzles. But at least neither of the puzzles is solvable completely without solving the other grid.

Puzzles can be found below.

The first puzzle is an Outside Tapa. I don't think this one is as nice as Serkan's puzzle from TVC VII but I think it's nice none-the-less. The variant isn't as influential in this puzzle, but has some points that should be important for the solve. But a few of the outside clues are purely to settle uniqueness.

The second puzzle is a Total False Tapa. This variant seems to always require a lot of clues. When I was done with the design I actually went out to edit the puzzle a bit, replacing multiple clues with 8's as the actual value of the clue was unnecessary, meaning that an 8 would work just as well. I think it makes the puzzle a bit nicer a solve. I think the end of the solve it trickiest.

The third Puzzle is a Twopa. It's a really tricky type to design, but I don't think the solve is particularly challenging. The main problem here is that you can't just add clues wherever you want as it might not work for both puzzles or it might not solve differently for both puzzles. But at least neither of the puzzles is solvable completely without solving the other grid.

Puzzles can be found below.

## Wednesday 11 September 2013

### TVC XV Practise: Part 1

Here are the first 4 practise puzzles for TVC XV. I will try to get the other 6 ready for tomorrow, but it can be that this week the practise puzzles come in three instalments. As always certain types cause more issues to construct than others. Especially the Twopa is pretty annoying to construct. I also had some trouble getting the No-Islands started, but I think that one turned out nice.

The first puzzle is a Hexa Tapa. I expect the puzzle in the contest to be a larger puzzle. I think in smaller size they really aren't generally very interesting, so I somewhat expect Serkan to go big and do something nice with it. I don't think this puzzle is too hard, but it isn't too bad. The two 1s on the outside were clues I'd have rather left out, but were necessary for uniqueness.

The second puzzle is a Tapa Skyscrapers. And I guess it's appropriate it's second as it's all 2s. I actually made the Kakuro-Style first and figured I could do the same with this genre. I think this one is the nicer of the two puzzles. It was at least fun to construct.

The third puzzle is a Kakuro-Style Tapa. It has the same inside clues as the Tapa Skyscrapers. I spend ages trying to construct this one, but I couldn't get it out the way I wanted it. People who are familiar with my constructing, know that I'm not all too happy with those 2 inside squares. I just liked how the opening worked and after many tries this was the nicest way to finish it.

The fourth puzzle is a No-Islands Tapa. I had some trouble getting this one started. It also took a little while to get all the constraints in correctly, so my first few tries I would realise too late that I had already broken a constraint or two. If you want to know which constraints, look a bit at the Cave/Corral/Bag genre; that should give you some ideas.

Puzzles can be found below.

The first puzzle is a Hexa Tapa. I expect the puzzle in the contest to be a larger puzzle. I think in smaller size they really aren't generally very interesting, so I somewhat expect Serkan to go big and do something nice with it. I don't think this puzzle is too hard, but it isn't too bad. The two 1s on the outside were clues I'd have rather left out, but were necessary for uniqueness.

The second puzzle is a Tapa Skyscrapers. And I guess it's appropriate it's second as it's all 2s. I actually made the Kakuro-Style first and figured I could do the same with this genre. I think this one is the nicer of the two puzzles. It was at least fun to construct.

The third puzzle is a Kakuro-Style Tapa. It has the same inside clues as the Tapa Skyscrapers. I spend ages trying to construct this one, but I couldn't get it out the way I wanted it. People who are familiar with my constructing, know that I'm not all too happy with those 2 inside squares. I just liked how the opening worked and after many tries this was the nicest way to finish it.

The fourth puzzle is a No-Islands Tapa. I had some trouble getting this one started. It also took a little while to get all the constraints in correctly, so my first few tries I would realise too late that I had already broken a constraint or two. If you want to know which constraints, look a bit at the Cave/Corral/Bag genre; that should give you some ideas.

Puzzles can be found below.

## Monday 9 September 2013

### TVC XV Practise: Introduction

This weekend is TVC XV at Logicmasters India. It features five variants new to the TVC. The other five have appeared before. Many of the new variants have been posted on blogs before though. I will again try to write a practise puzzle for each variant. But here's again a collection of links to examples of these Tapa variants. If someone else knows of more exaples, feel free to add some links to them in the comments.

You will also again be able to vote for some of the variants which will appear in TVC XVI. I think this might be because some of the variants are getting a bit sketchy and Serkan wants to judge if people like the idea of certain variants or not in advance. Sometimes it's tricky to make a variant idea work, especially if you don't have any examples of it yet.

I would have found it interesting that TVC XVI would have featured a single variant as the main focus and make double variant puzzles. My best suggestion would have been Pata as that only changes what the clues indicate. So a Pata Islands or Pata Elimination is easily possible. I think that might be fun too.

Links to puzzles:

Tapa Regional:

http://mellowmelon.wordpress.com/2012/02/22/puzzle-389/

http://logicmastersindia.com/lmitests/?test=M201209P

http://puzzleparasite.blogspot.com.au/2013/08/tvc-xiv-practise-part-2.html

http://logicmastersindia.com/TVC/XIV/

Hexa Tapa:

http://oapc.wpc2009.org/archive.php?id=52

http://valezius.blogspot.com.au/2013/02/nr-992-hexa-tapa.html

Outside Tapa:

http://logicmastersindia.com/lmitests/?test=TVC8

Total False Tapa:

http://valezius.blogspot.com.au/2013/02/nr-989-total-false-tapa.html

http://logicmastersindia.com/TVC/IX/

http://logicmastersindia.com/TVC/X

http://puzzleparasite.blogspot.com.au/2012/02/tvc-ix-practise.html

http://puzzleparasite.blogspot.com.au/2012/02/tvc-x-practise.html

Tapa [Skyscrapers]:

http://yureklis.wordpress.com/2012/06/18/puzzle-28-tapa-skyscrapers/

http://prasannaseshadri.wordpress.com/2012/06/17/puzzle-no-172-tapa-skyscrapers/

http://prasannaseshadri.wordpress.com/2013/03/11/puzzle-no-316-336-polish-championship-set/

Tapa Doubleback:

http://puzzleparasite.blogspot.com.au/2011/12/puzzle-70-tapa-double-back.html

http://valezius.blogspot.com.au/2011/12/aa.html (without Tapa clues)

http://inabapuzzle.com/honkaku/disco.html (without Tapa clues)

Compass Tapa:

http://buyaketa.blogspot.com/2012/02/compass-tapa.html

http://mellowmelon.files.wordpress.com/2012/03/tvc12-practice.pdf

http://puzzleparasite.blogspot.com.au/2012/03/tvc-xii-practise-part-3.html

http://logicmastersindia.com/lmitests/?test=TVC12

http://yureklis.wordpress.com/2012/06/03/puzzle-10-compass-tapa/

Kakuro-Style Tapa:

http://anuragthefirst.blogspot.com.au/2012/09/kakuro-style-tapa_2575.html

http://anuragthefirst.blogspot.com.au/2012/09/kakuro-style-tapa_3.html

Twopa:

http://prasannaseshadri.wordpress.com/2012/03/30/puzzle-no-111-two-pa/

http://prasannaseshadri.wordpress.com/2012/04/01/puzzle-no-115-two-pa2/

You will also again be able to vote for some of the variants which will appear in TVC XVI. I think this might be because some of the variants are getting a bit sketchy and Serkan wants to judge if people like the idea of certain variants or not in advance. Sometimes it's tricky to make a variant idea work, especially if you don't have any examples of it yet.

I would have found it interesting that TVC XVI would have featured a single variant as the main focus and make double variant puzzles. My best suggestion would have been Pata as that only changes what the clues indicate. So a Pata Islands or Pata Elimination is easily possible. I think that might be fun too.

Links to puzzles:

Tapa Regional:

http://mellowmelon.wordpress.com/2012/02/22/puzzle-389/

http://logicmastersindia.com/lmitests/?test=M201209P

http://puzzleparasite.blogspot.com.au/2013/08/tvc-xiv-practise-part-2.html

http://logicmastersindia.com/TVC/XIV/

Hexa Tapa:

http://oapc.wpc2009.org/archive.php?id=52

http://valezius.blogspot.com.au/2013/02/nr-992-hexa-tapa.html

Outside Tapa:

http://logicmastersindia.com/lmitests/?test=TVC8

Total False Tapa:

http://valezius.blogspot.com.au/2013/02/nr-989-total-false-tapa.html

http://logicmastersindia.com/TVC/IX/

http://logicmastersindia.com/TVC/X

http://puzzleparasite.blogspot.com.au/2012/02/tvc-ix-practise.html

http://puzzleparasite.blogspot.com.au/2012/02/tvc-x-practise.html

Tapa [Skyscrapers]:

http://yureklis.wordpress.com/2012/06/18/puzzle-28-tapa-skyscrapers/

http://prasannaseshadri.wordpress.com/2012/06/17/puzzle-no-172-tapa-skyscrapers/

http://prasannaseshadri.wordpress.com/2013/03/11/puzzle-no-316-336-polish-championship-set/

Tapa Doubleback:

http://puzzleparasite.blogspot.com.au/2011/12/puzzle-70-tapa-double-back.html

http://valezius.blogspot.com.au/2011/12/aa.html (without Tapa clues)

http://inabapuzzle.com/honkaku/disco.html (without Tapa clues)

Compass Tapa:

http://buyaketa.blogspot.com/2012/02/compass-tapa.html

http://mellowmelon.files.wordpress.com/2012/03/tvc12-practice.pdf

http://puzzleparasite.blogspot.com.au/2012/03/tvc-xii-practise-part-3.html

http://logicmastersindia.com/lmitests/?test=TVC12

http://yureklis.wordpress.com/2012/06/03/puzzle-10-compass-tapa/

Kakuro-Style Tapa:

http://anuragthefirst.blogspot.com.au/2012/09/kakuro-style-tapa_2575.html

http://anuragthefirst.blogspot.com.au/2012/09/kakuro-style-tapa_3.html

Twopa:

http://prasannaseshadri.wordpress.com/2012/03/30/puzzle-no-111-two-pa/

http://prasannaseshadri.wordpress.com/2012/04/01/puzzle-no-115-two-pa2/

## Saturday 7 September 2013

### Daily League Sudoku #28: Knight's Tour Sudoku

This week again an easier puzzle, at least it should be. I think the variant idea is pretty simple and might have been done before. I debated for a while whether or not to have the knights to move from a grey square to 1 through 9 and then back to a grey square, or to do it the way I did now. I thought this was a nicer way, as I thought the last move from 9 to a random number seemed a bit odd. The design was a bit tricky as it was easy to forget to check all numbers and whether it was still possible to connect the paths. The puzzle is fun although it didn't turn out completely the way I wanted. But as it had to also be a unique Sudoku, it worked out good. I only needed to give 12 clues, which I wasn't expecting. The pattern of 12 was the opening lay out, but I figured I would have to add some more to eventually get the Sudoku unique.

I hope you all enjoy it.

Recap of the Daily League:

Sunday: Average Sudoku by Seungjae Kwak

Monday: Poker Sudoku by Sina Hera

Tuesday: Palindrome Sudoku by Prasanna Seshadri

Wednesday: Little Killer Sudoku by Bastien Vial-Jaime

Thursday: Diagonal Sudoku by Rishi Puri

Friday: Outside Sudoku by Tom Collyer

Rules for Sudoku

In this Sudoku two knights are placed on a grey square with a digit 1. The knights then follow a path of knight's moves towards at least one of the other grey squares with a 9. The path travels through all digits 1 through 9 in order, including the digits in the grey squares. Each 9 should be reached by at least one knight.

I hope you all enjoy it.

Recap of the Daily League:

Sunday: Average Sudoku by Seungjae Kwak

Monday: Poker Sudoku by Sina Hera

Tuesday: Palindrome Sudoku by Prasanna Seshadri

Wednesday: Little Killer Sudoku by Bastien Vial-Jaime

Thursday: Diagonal Sudoku by Rishi Puri

Friday: Outside Sudoku by Tom Collyer

Rules for Sudoku

In this Sudoku two knights are placed on a grey square with a digit 1. The knights then follow a path of knight's moves towards at least one of the other grey squares with a 9. The path travels through all digits 1 through 9 in order, including the digits in the grey squares. Each 9 should be reached by at least one knight.

## Saturday 31 August 2013

### Daily League Sudoku #27: Thermo-Sudoku

I promised something easier this week and I think this should be good. This Thermo-Sudoku has a simple opening that should give away a few quick digits. I was trying to make it without any given digits, but the given layout wouldn't allow it. The one central 5 made it unique though and it fits with the decreasing size of squares. It might be possible to line up the thermometers to make it unique without digits or by adding an extra one in the center, but I like how it turned out. I just hope I haven't misjudged the difficulty again, as I have done before. Enjoy.

Recap of the last Daily League week:

Sunday: Alternative Sudoku by Seungjae Kwak

Tuesday: Even Sudoku with Disjoint Groups by Prasanna Seshadri

Wednesday: Arrow Sudoku by Bastien Vial-Jaime

Thursday: 1-Consecutive Sudoku by Hall Hur

Friday: Irregular Sudoku by Tom Collyer

All puzzles can also be solved at SudokuCup.

Rules for Sudoku

In this Sudoku, there are a number of thermometers. Along each thermometer, digits have to be strictly increasing from the bulb upwards.

Recap of the last Daily League week:

Sunday: Alternative Sudoku by Seungjae Kwak

Tuesday: Even Sudoku with Disjoint Groups by Prasanna Seshadri

Wednesday: Arrow Sudoku by Bastien Vial-Jaime

Thursday: 1-Consecutive Sudoku by Hall Hur

Friday: Irregular Sudoku by Tom Collyer

All puzzles can also be solved at SudokuCup.

Rules for Sudoku

In this Sudoku, there are a number of thermometers. Along each thermometer, digits have to be strictly increasing from the bulb upwards.

## Friday 30 August 2013

### TVC XIV Practise: Part 2

This post is a bit delayed. That happens when you discover mistakes in your puzzles. I think I fixed them, but sometimes you just get stuck in a spiral of bad deductions that won't get out of your head. I hope most people will still get some use out of them though, with the late arrival.

The first puzzle is a Tapa Loop. I think this is generally a pretty smooth variant and hardly ever causes real issues. This puzzle is not very difficult and if you understand how the variant works, it should go pretty quick.

The second puzzle is a Regional Tapa. The genre is a little bit restrictive in design but I had fun working with it. I did have a problem where I apparently can't count and had to change some of the regions because one region had one cell too many coloured.

The third puzzle is a Cyclic Tapa. Good for people who like classic Tapa as all deductions are like normal. Some clues just have to work for two grids instead of one. I made a stupid error in construction where I placed one pair of copied clues in different squares. But as the rules don't state they have to be in the same square I think this is still a valid puzzle. It would just look nicer. I like how it turned out. I should, it took me ages to get one out that was a bit interesting.

The fourth puzzle is a Pentapa. I always like puzzles with pentominoes, this one is no different. Certain pentominoes are more easily formed by a Tapa wall. These you can usually deduce pretty quickly and then have to try to avoid for the rest of the solve. The Tapa element still comes forward enough though and it's not just playing with pentominoes.

The fifth puzzle is a Elimination Tapa. This was the one that had the biggest error. I changed one of the digits to make a clue work, except that ruined the deductions of a lot of other clues, so had to fix that. It was luckily not the worst fix. I think it's still a nice puzzle. Good practise for bordering clues.

I hope practising all puzzles will help people in the upcoming TVC XIV. Enjoy.

Puzzles can be found below

The first puzzle is a Tapa Loop. I think this is generally a pretty smooth variant and hardly ever causes real issues. This puzzle is not very difficult and if you understand how the variant works, it should go pretty quick.

The second puzzle is a Regional Tapa. The genre is a little bit restrictive in design but I had fun working with it. I did have a problem where I apparently can't count and had to change some of the regions because one region had one cell too many coloured.

The third puzzle is a Cyclic Tapa. Good for people who like classic Tapa as all deductions are like normal. Some clues just have to work for two grids instead of one. I made a stupid error in construction where I placed one pair of copied clues in different squares. But as the rules don't state they have to be in the same square I think this is still a valid puzzle. It would just look nicer. I like how it turned out. I should, it took me ages to get one out that was a bit interesting.

The fourth puzzle is a Pentapa. I always like puzzles with pentominoes, this one is no different. Certain pentominoes are more easily formed by a Tapa wall. These you can usually deduce pretty quickly and then have to try to avoid for the rest of the solve. The Tapa element still comes forward enough though and it's not just playing with pentominoes.

The fifth puzzle is a Elimination Tapa. This was the one that had the biggest error. I changed one of the digits to make a clue work, except that ruined the deductions of a lot of other clues, so had to fix that. It was luckily not the worst fix. I think it's still a nice puzzle. Good practise for bordering clues.

I hope practising all puzzles will help people in the upcoming TVC XIV. Enjoy.

Puzzles can be found below

## Thursday 29 August 2013

### TVC XIV Practise: Part 1

I was hoping to post these a little bit earlier, but construction of a few puzzles caused more trouble than planned. I tried to make a puzzle for all types not provided in the introduction, except I couldn't get the Cyclic Tapa to go. I tried to make it 10x10, except I might go for a smaller size to at least have something out. So instead I added a Tapa Turns to this part. The remaining five types will hopefully be out tonight or Friday morning Canberra time.

The first puzzle is a Tapa Clones. This variant allows you to only use five different clues, three of which obey this rule under normal Tapa conditions. So the influence doesn't seem to be very great, but I think it worked out okay in this puzzle.

The second puzzle is a Tapa Turns. I think it worked out pretty well. You can make the "turns" clues be very influential as the no 2x2 squares rule restricts how the clues can work.

The third puzzle is a Wordic Tapa. It's a bit of a tricky puzzle to make. The fact that 4 can be a 0 always is annoying and made the construction tricky. There were a number of times where I had to scrap a puzzle because I had missed alternate solutions where a 4 would turn into a 0 instead of 4 or 5. It could be that the actual TVC puzzle uses a different language and thus the clues don't correspond to the same digits.

The fourth puzzle is a Tapa or not Tapa. A lot of the clues end up having to be coloured. Probably possible to make a puzzle where every clue ends up getting coloured. I think it might sometimes be too easy that a clue can just get coloured as colouring wouldn't do anything to make the solution invalid, instead of having to deduce why it can't be valid. I think it worked out okay, even though I had to sacrifice symmetry for uniqueness.

The fifth puzzle is a Tapa in the Cave. The variant doesn't allow for clues over 3 and 3 clues are a bit more restrictive than normal. The variant seems pretty fun, even though I didn't particularly like the idea at the start. But that seems to more often happen with Zoltan's variant ideas. I had tried a similar idea too before, but couldn't get it out in an interesting way so never posted the puzzle. The puzzle has clue that ruins symmetry, but it was necessary for uniqueness. I couldn't add a clue symmetrically as that would be a valid clue if one was placed there.

Puzzles can be found below.

The first puzzle is a Tapa Clones. This variant allows you to only use five different clues, three of which obey this rule under normal Tapa conditions. So the influence doesn't seem to be very great, but I think it worked out okay in this puzzle.

The second puzzle is a Tapa Turns. I think it worked out pretty well. You can make the "turns" clues be very influential as the no 2x2 squares rule restricts how the clues can work.

The third puzzle is a Wordic Tapa. It's a bit of a tricky puzzle to make. The fact that 4 can be a 0 always is annoying and made the construction tricky. There were a number of times where I had to scrap a puzzle because I had missed alternate solutions where a 4 would turn into a 0 instead of 4 or 5. It could be that the actual TVC puzzle uses a different language and thus the clues don't correspond to the same digits.

The fourth puzzle is a Tapa or not Tapa. A lot of the clues end up having to be coloured. Probably possible to make a puzzle where every clue ends up getting coloured. I think it might sometimes be too easy that a clue can just get coloured as colouring wouldn't do anything to make the solution invalid, instead of having to deduce why it can't be valid. I think it worked out okay, even though I had to sacrifice symmetry for uniqueness.

The fifth puzzle is a Tapa in the Cave. The variant doesn't allow for clues over 3 and 3 clues are a bit more restrictive than normal. The variant seems pretty fun, even though I didn't particularly like the idea at the start. But that seems to more often happen with Zoltan's variant ideas. I had tried a similar idea too before, but couldn't get it out in an interesting way so never posted the puzzle. The puzzle has clue that ruins symmetry, but it was necessary for uniqueness. I couldn't add a clue symmetrically as that would be a valid clue if one was placed there.

Puzzles can be found below.

## Tuesday 27 August 2013

### TVC XIV Practise: Introduction

Upcoming weekend will be TVC XIV on Logicmasters India. I'll be trying to write an example of each puzzle type like last year. I missed TVC XIII as I was a bit late realising it would start and had other puzzles to write at that moment. Puzzles will be posted over the next few days.

I'm using this post to direct you to some of the previous examples of some of the variants used.

Tapa Loop:

http://logicmastersindia.com/lmitests/?test=TVC13

http://logicmastersindia.com/lmitests/?test=M201207P

http://puzzleparasite.blogspot.com.au/2012/07/lmi-practise-logiraces.html

http://yureklis.wordpress.com/2012/07/22/puzzle-43-tapa-loop/

Tapa Turns:

http://anuragthefirst.blogspot.com.au/2012/09/tapa-turns.html

Tapa [Regional]:

http://mellowmelon.wordpress.com/2012/02/22/puzzle-389/

http://logicmastersindia.com/lmitests/?test=M201209P

Pentapa:

http://logicmastersindia.com/lmitests/?test=TVC7

Elimination Tapa:

http://chaosatthesky.wordpress.com/2013/05/15/deception-5/

http://logicmastersindia.com/lmitests/?test=M201305P

http://puzzleparasite.blogspot.com.au/2011/09/puzzle-11-tapa-cross-out.html

I'm using this post to direct you to some of the previous examples of some of the variants used.

Tapa Loop:

http://logicmastersindia.com/lmitests/?test=TVC13

http://logicmastersindia.com/lmitests/?test=M201207P

http://puzzleparasite.blogspot.com.au/2012/07/lmi-practise-logiraces.html

http://yureklis.wordpress.com/2012/07/22/puzzle-43-tapa-loop/

Tapa Turns:

http://anuragthefirst.blogspot.com.au/2012/09/tapa-turns.html

Tapa [Regional]:

http://mellowmelon.wordpress.com/2012/02/22/puzzle-389/

http://logicmastersindia.com/lmitests/?test=M201209P

Pentapa:

http://logicmastersindia.com/lmitests/?test=TVC7

Elimination Tapa:

http://chaosatthesky.wordpress.com/2013/05/15/deception-5/

http://logicmastersindia.com/lmitests/?test=M201305P

http://puzzleparasite.blogspot.com.au/2011/09/puzzle-11-tapa-cross-out.html

## Saturday 24 August 2013

### Daily League Sudoku #26: Jigsaw Killer Sudoku

This weekend a combination of two standard Sudoku variants. Although I wouldn't say it's a standard puzzle for either variant. When combining different puzzle types or variants, I think it's important to make sure they come into play together and aren't just in the puzzle together. So for this puzzle I chose a cage layout that could never work in a standard Killer Sudoku, as it could never be unique. But the Jigsaw layout allows you to use this cage layout. This puzzle also uses a tricky set of opening moves that you wouldn't normally see in a Killer Sudoku. I think this is again a harder puzzle and the opening will probably stump a few people, but it's clear logic once you find it. I promise next week I'll come with an easier puzzle. Enjoy!

Recap of the last Daily League week:

Sunday: Difference Sudoku by Seungjae Kwak

Monday: Anti-Knight Windoku by Jakub Hrazdira

Tuesday: Quadruple Sudoku by Prasanna Seshadri

Wednesday: Overlapping Diagonal Sudoku by Bastien Vial-Jaime

Thursday: Diagonally Non-Consecutive Sudoku by Rishi Puri

Friday: Classic Sudoku by Tom Collyer

Rules for Sudoku

Instead of given numbers, you now have a few dashed cages. The number in the cage indicates the sum of the digits in the cage, Digits can't be repeated in any dashed cage.

Recap of the last Daily League week:

Sunday: Difference Sudoku by Seungjae Kwak

Monday: Anti-Knight Windoku by Jakub Hrazdira

Tuesday: Quadruple Sudoku by Prasanna Seshadri

Wednesday: Overlapping Diagonal Sudoku by Bastien Vial-Jaime

Thursday: Diagonally Non-Consecutive Sudoku by Rishi Puri

Friday: Classic Sudoku by Tom Collyer

Rules for Sudoku

Instead of given numbers, you now have a few dashed cages. The number in the cage indicates the sum of the digits in the cage, Digits can't be repeated in any dashed cage.

Click to enlarge |

## Saturday 17 August 2013

### Daily League Sudoku #25: MaxiMini Sum Sudoku

I think this is also a new idea, but I can hardly know all Sudoku ideas. It's not really anything revolutionary, but I like how it worked out. I already did a similar idea before except it used maximum difference. I also added the minimum constraint here as it helped set up openings. The more frequent Daily League puzzles might get a feeling of deja-vu. This puzzle will probably again turn out on the harder side as the steps are pretty restrictive in order for the opening and it's not till the end that there's a bit more freedom on which clues to use. I've noticed that generally seems to be the deciding factor in what makes my puzzle hard or not. I hope people enjoy it though, I think it's a good solve.

Recap of the last Daily League week:

Sunday: Balanced Sudoku by Seungjae Kwak

Monday: Even Queens Sudoku by Sina Hera

Tuesday: Renban Groups Sudoku by Prasanna Seshadri

Wednesday: Killer Sudoku by Bastien Vial-Jaime

Thursday: One Way Multi-Diagonal Sudoku by Rishi Puri

Friday: Extra Regions Sudoku by Tom Collyer

Daily League PDF's:

Week 29

Week 30

Week 31

Rules for Sudoku

In this Sudoku there are clues on the outside of the grid. Numbers above or left of the grid indicate the maximum sum of two adjacent digits in that row or column. Numbers below or right of the grid indicate the minimum sum of two adjacent digits in that row or column. Each given sum appears at least once in that row or column.

Recap of the last Daily League week:

Sunday: Balanced Sudoku by Seungjae Kwak

Monday: Even Queens Sudoku by Sina Hera

Tuesday: Renban Groups Sudoku by Prasanna Seshadri

Wednesday: Killer Sudoku by Bastien Vial-Jaime

Thursday: One Way Multi-Diagonal Sudoku by Rishi Puri

Friday: Extra Regions Sudoku by Tom Collyer

Daily League PDF's:

Week 29

Week 30

Week 31

Rules for Sudoku

In this Sudoku there are clues on the outside of the grid. Numbers above or left of the grid indicate the maximum sum of two adjacent digits in that row or column. Numbers below or right of the grid indicate the minimum sum of two adjacent digits in that row or column. Each given sum appears at least once in that row or column.

## Monday 12 August 2013

### World Puzzle Championship 2013: 80 puzzle around the world and blog

Here are some announcements about the 2013 World Puzzle Championship.

This year's WSC/WPC will be held from October 12th-October 19th in Beijing, China. Any additional information can be found on http://wscwpc2013.sudoku.org.cn/.

There will also be a blog with information specifically about the World Puzzle Championship hosted by the Hungarian organisation on the following link: http://wpc-2013.blogspot.hu.

Lastly, there's a new initiative tested in this year's WPC. There will be numerous outside puzzle contributing teams, each preparing a set of puzzles to solve. This round is called "Around The World in 80 Puzzles", a play on the famous Jules Verne novel. There are four contributing teams, from four different countries, each providing a set of 20 puzzles each. One of the four sets is provided by me and three other Dutch puzzle authors: Hans Eendebak, Tim Peeters and Richard Stolk. If you want to read more about it, you can on the following link: http://wpc-2013.blogspot.hu/2013/08/around-world-in-80-puzzles-introduction.html.

This year's WSC/WPC will be held from October 12th-October 19th in Beijing, China. Any additional information can be found on http://wscwpc2013.sudoku.org.cn/.

There will also be a blog with information specifically about the World Puzzle Championship hosted by the Hungarian organisation on the following link: http://wpc-2013.blogspot.hu.

Lastly, there's a new initiative tested in this year's WPC. There will be numerous outside puzzle contributing teams, each preparing a set of puzzles to solve. This round is called "Around The World in 80 Puzzles", a play on the famous Jules Verne novel. There are four contributing teams, from four different countries, each providing a set of 20 puzzles each. One of the four sets is provided by me and three other Dutch puzzle authors: Hans Eendebak, Tim Peeters and Richard Stolk. If you want to read more about it, you can on the following link: http://wpc-2013.blogspot.hu/2013/08/around-world-in-80-puzzles-introduction.html.

## Saturday 10 August 2013

### Daily League Sudoku #24: Greater Than Sudoku

This week a common variant again. I tend to enjoy solving these puzzles, even though design-wise there's usually not that much in them. I just like sudokus without given digits.

I've been busy writing puzzles for other purposes and then I tend to steer towards a simpler, more common variant. This type is really easy to put together. Many solutions will be unique in this type. There's a few constraints the solution should have to qualify, but it's generally just a matter of checking if it has them and then checking how it solves logically. Some have a path that's a bit too easy and others are too hard. I think this one has a nice logical path. Enjoy.

Recap of the last Daily League week:

Sunday: PS Sudoku by Seungjae Kwak

Monday: Jigsaw Sudoku by Jakub Hrazdira

Tuesday: Diagonal Compromise Sudoku by Prasanna Seshadri

Wednesday: Diagonal Sudoku by Bastien Vial-Jaime

Thursday: Non-Consecutive Sudoku by Rishi Puri

Friday: Quad Sum Sudoku by Benz Liang

Rules for Sudoku

In this Sudoku the digits have to obey all Greater than/Less than signs between cells.

I've been busy writing puzzles for other purposes and then I tend to steer towards a simpler, more common variant. This type is really easy to put together. Many solutions will be unique in this type. There's a few constraints the solution should have to qualify, but it's generally just a matter of checking if it has them and then checking how it solves logically. Some have a path that's a bit too easy and others are too hard. I think this one has a nice logical path. Enjoy.

Recap of the last Daily League week:

Sunday: PS Sudoku by Seungjae Kwak

Monday: Jigsaw Sudoku by Jakub Hrazdira

Tuesday: Diagonal Compromise Sudoku by Prasanna Seshadri

Wednesday: Diagonal Sudoku by Bastien Vial-Jaime

Thursday: Non-Consecutive Sudoku by Rishi Puri

Friday: Quad Sum Sudoku by Benz Liang

Rules for Sudoku

In this Sudoku the digits have to obey all Greater than/Less than signs between cells.

## Saturday 3 August 2013

### Daily League Sudoku #23: Sum or Difference Sudoku

This week a Sudoku variant themed around today's date. I did it once before for Valentine's day. I somewhat stumbled into it, while just messing around with a few ideas for a Sudoku. I put down a 3 and an 8 and figured I could push it through the whole puzzle. It's split down the left bottom and right top diagonal. It's not too hard a puzzle after realising the opening. Enjoy.

The puzzle is a bit late, but I had to remake part of it as part of the logic was incorrect. Hopefully this one is without error.

Recap of the last Daily League week:

Sunday: One of Eight Sudoku by Seungjae Kwak

Monday: Pairs Sudoku by Jakub Hrazdira

Tuesday: Domino Sudoku by Prasanna Seshadri

Wednesday: Frame Sudoku by Bastien Vial-Jaime

Thursday: Odd-Even Antiknight Sudoku by Rishi Puri

Friday: Nonconsecutive Sudoku by Tom Collyer

Daily League PDF's:

Week 28

Rules for Sudoku

In this Sudoku, a number between two cells indicate either the sum of or the difference between these two cells.

[Edit: Puzzle image adjusted as one of the clues was missing]

The puzzle is a bit late, but I had to remake part of it as part of the logic was incorrect. Hopefully this one is without error.

Recap of the last Daily League week:

Sunday: One of Eight Sudoku by Seungjae Kwak

Monday: Pairs Sudoku by Jakub Hrazdira

Tuesday: Domino Sudoku by Prasanna Seshadri

Wednesday: Frame Sudoku by Bastien Vial-Jaime

Thursday: Odd-Even Antiknight Sudoku by Rishi Puri

Friday: Nonconsecutive Sudoku by Tom Collyer

Daily League PDF's:

Week 28

Rules for Sudoku

In this Sudoku, a number between two cells indicate either the sum of or the difference between these two cells.

[Edit: Puzzle image adjusted as one of the clues was missing]

## Saturday 27 July 2013

### Daily League Sudoku #22: Diagonal Sudoku

This week again something standard and easy. I don't often write classic Sudokus or standard variants. I think it is because I can't really put anything that creative in my designs for them. I can make them visually pleasing, but that is generally it. I like to put interesting logic in my puzzles, but I have trouble achieving that with normal Sudoku. That's probably because there's too many of them out there, that I feel I can't really offer anything new to the mix. Even when I try I tend to have to give up on it, because otherwise I can't get it unique. I think this one worked out okay though. I expect very fast times though from the best solvers. I don't think there are really many stumbling blocks.

Recap of the last Daily League week:

Saturday: Classic Sudoku by Tom Collyer

Sunday: Edge Product Sudoku by Seungjae Kwak

Monday: Just One Cell Samurai Sudoku by Tiit Vunk

Tuesday: Repeated Neighbours Sudoku by Prasanna Seshadri

Wednesday: Outside or Skyscraper Sudoku by Bastien Vial-Jaime

Thursday: Twin Detector Sudoku by Sina Hera

Friday: Even Sudoku by Tom Collyer

Daily League PDFs:

Week 25

Week 26

Week 27

Rules for Sudoku

In this Sudoku you also have to put the digits 1~9 once on the marked diagonals.

Recap of the last Daily League week:

Saturday: Classic Sudoku by Tom Collyer

Sunday: Edge Product Sudoku by Seungjae Kwak

Monday: Just One Cell Samurai Sudoku by Tiit Vunk

Tuesday: Repeated Neighbours Sudoku by Prasanna Seshadri

Wednesday: Outside or Skyscraper Sudoku by Bastien Vial-Jaime

Thursday: Twin Detector Sudoku by Sina Hera

Friday: Even Sudoku by Tom Collyer

Daily League PDFs:

Week 25

Week 26

Week 27

Rules for Sudoku

In this Sudoku you also have to put the digits 1~9 once on the marked diagonals.

## Friday 19 July 2013

### Daily League Sudoku #21: Hi-Lo Inner Frame Sudoku

I'm back with a Daily League Sudoku this week. I'm posting the Friday puzzle as Tom needed a bit more time and my puzzle is ready. This week I've written a combination of two nice types. The Inner Frame I first saw on the 2012 US Sudoku Qualifiers. The Hi-Lo Frame Sudoku I first encountered on the 2011 Dutch Sudoku championships.

I think they work well together. The Inner Frame idea leaves you to use some combinations that would otherwise not be possible, because there is more room for repeated digits within the different sums. I chose for an easier layout of clues that all overlap, which I think makes the solve a bit more friendly. I think it worked out well. I hope you enjoy it too.

Daily League PDFs:

Week 20

Week 21

Week 22

Week 23

As a final note, all puzzles are also solvable each day on SudokuCup. The puzzles appear a day later than in the group.

Rules for Sudoku

In this Sudoku, the numbers on the outside indicate the sum of the highest and the lowest of the three digits in the 2nd, 3rd and 4th cell seen from that side.

I think they work well together. The Inner Frame idea leaves you to use some combinations that would otherwise not be possible, because there is more room for repeated digits within the different sums. I chose for an easier layout of clues that all overlap, which I think makes the solve a bit more friendly. I think it worked out well. I hope you enjoy it too.

Daily League PDFs:

Week 20

Week 21

Week 22

Week 23

As a final note, all puzzles are also solvable each day on SudokuCup. The puzzles appear a day later than in the group.

Rules for Sudoku

In this Sudoku, the numbers on the outside indicate the sum of the highest and the lowest of the three digits in the 2nd, 3rd and 4th cell seen from that side.

## Saturday 13 July 2013

### Puzzle #162: Pentopia

I should be in Australia by now, getting used to driving on the left, kangaroos and koalas, still not liking meat pies and trying to understand what cold means in Australia. This post is written 6 days ago though, so I might be completely wrong.

These two puzzles I have also written earlier. Checking the number of tags on my blog, it's no surprise that I would have chosen to write Yajilin and Pentopia puzzles. They're just types that come very easy to me and I always find fun to write and hope people actually like to solve. But they generally seem well received. Pentopia featured on the USPC this year, after also featuring on the WPC last year. They've also been published in Breinbrekers. So I guess that means it is getting more exposure than just my blog.

The puzzles are pretty good. The first one is a 10 clue puzzle that has a fun opening, but I couldn't get it unique with that 10th clue in a symmetrical position, so I moved one of the clues to acchieve a unique puzzle. The second puzzle has an easy opening, but takes a bit more finesse to finish.

Rules for Pentopia

These two puzzles I have also written earlier. Checking the number of tags on my blog, it's no surprise that I would have chosen to write Yajilin and Pentopia puzzles. They're just types that come very easy to me and I always find fun to write and hope people actually like to solve. But they generally seem well received. Pentopia featured on the USPC this year, after also featuring on the WPC last year. They've also been published in Breinbrekers. So I guess that means it is getting more exposure than just my blog.

The puzzles are pretty good. The first one is a 10 clue puzzle that has a fun opening, but I couldn't get it unique with that 10th clue in a symmetrical position, so I moved one of the clues to acchieve a unique puzzle. The second puzzle has an easy opening, but takes a bit more finesse to finish.

Rules for Pentopia

Puzzle #1

Puzzle #2

## Wednesday 10 July 2013

### Puzzle #161: Yajilin

At the point of this post I'll probably be somewhere above Asia. I'm too lazy to properly work out where my plane should be. I'm flying to Australia today. Hopefully there will be no problems and I'll get through customs there without any problems. Watching those border control shows really makes it look a bit scary. But I'm smart enough to not stock half my suitcase with food, so that should be okay, right?

The puzzles I'm posting today I made a while back, but never ended up being used where I made them for. As I now know they won't be in there, I can safely post them here. I think they worked out well. The first one was intended to symmetrical too, except I couldn't make it unique with the opening I had used. But then I noticed I could make it unique if I were to remove one of the clue squares. I think it worked out well. The second one uses some logic I don't often manage to put in these smaller Yajilin puzzles. I'm not sure if it will get noticed though. I think it works out nicely and is very reminiscent of my other Yajilins.

Rules for Yajilin

The puzzles I'm posting today I made a while back, but never ended up being used where I made them for. As I now know they won't be in there, I can safely post them here. I think they worked out well. The first one was intended to symmetrical too, except I couldn't make it unique with the opening I had used. But then I noticed I could make it unique if I were to remove one of the clue squares. I think it worked out well. The second one uses some logic I don't often manage to put in these smaller Yajilin puzzles. I'm not sure if it will get noticed though. I think it works out nicely and is very reminiscent of my other Yajilins.

Rules for Yajilin

*Puzzle 1*

*Puzzle 2*

## Sunday 7 July 2013

### Daily League Sudoku #20: Max Difference Sudoku and Ace Sudoku

I've been a bit busier lately and didn't find the time to write out my blog posts. So I'm using this to post the two Sudokus I had posted in the Daily League page in the last 2 weeks. They were both new ideas as far as I'm aware of, but both used familiar ideas, just used in a way not done before. I think I more often go for new ideas because I don't think I can add more to common Sudoku genres as there are already so many available online.

The first puzzle iss Max Difference Sudoku. It is a variant where the maximum difference between 2 adjacent digits are marked for some rows and columns. I liked the interactions as both high and low digits can be used to force placements if you use the clues appropriately. This is actually the second puzzle as I had made a bad deduction during construction, which made the whole puzzle fall apart. I think this one actually worked out better than the way first one should have worked.

The second puzzle is an Ace Sudoku. It's a tricky variant where each 3x3 region obeys one of two rules that have been used in other puzzle, namely that either adjacent digits can't have a difference of 1 or that adjacent digits can't sum to 11. You have to deduce which of these two rules applies for each region. I always like these choice puzzles. The most common way this has been used is All Odd Or All Even Sudoku. The construction for this one took a while. I had the opening set up pretty quickly, but then spend ages trying to figure out if I could place the remaining digits in this pattern, so that it was unique. Many tries ended up without a solution as some 3x3 regions wouldn't obey either of the rules and a few ended up with multiple solution. But after a while I managed to find this puzzle. It has a few tricky steps in the middle, where you need to find the critical steps to make progress. I like how it turned out though and think it really nicely uses the rules of the genre. The name of the puzzle is derived from the Ace in Blackjack.

Rules for Sudoku

Max Difference Sudoku

In this Sudoku numbers on the outside indicate the maximum difference between two adjacent digits in that row or column. The indicated difference has to appear at least once in that row or column.

Ace Sudoku

In this Sudoku within every 3x3 region neighbouring digits either don't have a difference of 1 or don't have a sum of 11. One of these rules is true for each 3x3 region, but the other one doesn't necessary have to be false. Which of these rules is true can differ between different 3x3 regions. There are no restrictions between adjacent digits in different 3x3 regions.

The first puzzle iss Max Difference Sudoku. It is a variant where the maximum difference between 2 adjacent digits are marked for some rows and columns. I liked the interactions as both high and low digits can be used to force placements if you use the clues appropriately. This is actually the second puzzle as I had made a bad deduction during construction, which made the whole puzzle fall apart. I think this one actually worked out better than the way first one should have worked.

The second puzzle is an Ace Sudoku. It's a tricky variant where each 3x3 region obeys one of two rules that have been used in other puzzle, namely that either adjacent digits can't have a difference of 1 or that adjacent digits can't sum to 11. You have to deduce which of these two rules applies for each region. I always like these choice puzzles. The most common way this has been used is All Odd Or All Even Sudoku. The construction for this one took a while. I had the opening set up pretty quickly, but then spend ages trying to figure out if I could place the remaining digits in this pattern, so that it was unique. Many tries ended up without a solution as some 3x3 regions wouldn't obey either of the rules and a few ended up with multiple solution. But after a while I managed to find this puzzle. It has a few tricky steps in the middle, where you need to find the critical steps to make progress. I like how it turned out though and think it really nicely uses the rules of the genre. The name of the puzzle is derived from the Ace in Blackjack.

Rules for Sudoku

Max Difference Sudoku

In this Sudoku numbers on the outside indicate the maximum difference between two adjacent digits in that row or column. The indicated difference has to appear at least once in that row or column.

Ace Sudoku

In this Sudoku within every 3x3 region neighbouring digits either don't have a difference of 1 or don't have a sum of 11. One of these rules is true for each 3x3 region, but the other one doesn't necessary have to be false. Which of these rules is true can differ between different 3x3 regions. There are no restrictions between adjacent digits in different 3x3 regions.

## Saturday 8 June 2013

### Daily League Sudoku #19: Renban Sudoku

This week we again have a more familiar puzzle type, namely Renban Sudoku. It took a few tries to get this one right again. It is too easy to run into no solutions if you don't pay attention. I think it's a nice puzzle, although I generally prefer my more puzzly Sudokus, where the extra rule pushes the solve more. I think people who are more into Sudoku will enjoy these better. I think they more enjoy solving the Sudoku like deductions than trying to figure out how I managed to use a trickier rule. I doubt this Sudoku should cause too much trouble to the best solvers and is again on the easier side.

Recap of the last Daily League week:

Sunday: Greater Than Sudoku by Seungjae Kwak

Monday: Cross Number Sudoku by Benz Liang

Tuesday: Thermo Killer Sudoku by Prasanna Seshadri

Wednesday: Quad Max Sudoku by Bastien Vial-Jaime

Thursday: Anti-Knight Sudoku by Jakub Hrazdira

Friday: Classic Sudoku by Tom Collyer

Daily League PDF:

Week 19

Rules for Sudoku

In this Sudoku each area of connected grey cells must contain a set of consecutive digits. The digits don't have to be in order.

Recap of the last Daily League week:

Sunday: Greater Than Sudoku by Seungjae Kwak

Monday: Cross Number Sudoku by Benz Liang

Tuesday: Thermo Killer Sudoku by Prasanna Seshadri

Wednesday: Quad Max Sudoku by Bastien Vial-Jaime

Thursday: Anti-Knight Sudoku by Jakub Hrazdira

Friday: Classic Sudoku by Tom Collyer

Daily League PDF:

Week 19

Rules for Sudoku

In this Sudoku each area of connected grey cells must contain a set of consecutive digits. The digits don't have to be in order.

## Saturday 1 June 2013

### Daily League Sudoku #18: Factory Killer Sudoku

This week's puzzle is again harder. Especially the opening is tricky. It really helps to understand some of the implications. I don't think I've seen this variant before, but one can never be sure.

I've been planning on writing a Killer Sudoku variant for a while, but it never came of it. Either because other people had a Killer Sudoku or that my attempts failed and I eventually switched to another Sudoku type. This puzzle took me about 3 hours to get right. I could have made it easier, but I really liked the 2-4-6-8 grouping in the middle nonets, but that led to some uniqueness issues for a while. I wasn't sure if I could get the 2 nonet to work, but it eventually fell nicely. It's tricky, but I think it has a nice solution path. Enjoy.

Recap of the last Daily League week:

Sunday: FINDoku by Seungjae Kwak

Monday: Thermometer Sudoku by Fred Stalder

Tuesday: Outside-Consecutive Sudoku by Prasanna Seshadri

Wednesday: Argyle Sudoku by Bastien Vial-Jaime

Thursday: Even Queens Sudoku by Jakub Hrazdira

Friday: Number 5 Is Not Alive Sudoku by Tom Collyer

In this Sudoku there are a number of dashes cages. A number in a dashed cage indicates a factor of the sum of the digits in its cage. Digits can't repeat within a cage.

## Saturday 25 May 2013

### Daily League Sudoku #17: Anti-Knight Sudoku

I didn't have very much inspiration this week to create a Sudoku, so I stepped back to a familiar type. I generally like Anti-Knight Sudokus. This one I constructed with a computer program as backup, to make sure that the there were still valid solutions. This means that when I can't find a valid solution, I check which of the givens I placed led to a situation where there no longer is a valid solution. This saves me from having to backtrack a lot as it can happen that you place multiple givens without being able to see that there is no longer a valid solution. I think the puzzle turned out nice. Enjoy.

Recap of the last Daily League week:

Sunday: Roman Non-Consecutive Sudoku by Seungjae Kwak

Monday: Extra Regions Sudoku by Fred Stalder

Tuesday: Arrow Sudoku by Prasanna Seshadri

Wednesday: Diamond Sudoku by Bastien Vial-Jaime

Thursday: No 3 Skyscraper Sudoku by Jan Zverina

Friday: Nonconsecutive Sudoku by Tom Collyer

Daily League PDF:

Week 18

Rules for Sudoku

In this Sudoku, two cells that are a Knights move away from eachother are always different.

Rules for Sudoku

In this Sudoku, two cells that are a Knights move away from eachother are always different.

## Saturday 18 May 2013

### Daily League Sudoku #16: Jigsaw Sudoku

This week no complicated rules but just a Jigsaw Sudoku. I like writing Jigsaw Sudokus. I always try to get the total clue count to 16 or less. I tend to draw out the cage patterns and not all Law of Leftover areas before starting so I can use it when needed. I feel it always helps the design along when you keep good track of that. I don't think the puzzle has anything special, but it's still fun to solve.

Recap of the last week.

Sunday: Clock Faces Sudoku by Seungjae Kwak

Monday: Sequence Sudoku by Fred Stalder

Tuesday: All Even or All Odd Sudoku by Prasanna Seshadri

Wednesday: Diagonal Sudoku by Bastien Vial-Jaime

Thursday: Odd Even Stars Sudoku by Jakub Hrazdira

Friday: Extra Regions Sudoku by Tom Collyer

Daily League PDF's:

Week 16

Week 17

Rules for Sudoku

Recap of the last week.

Sunday: Clock Faces Sudoku by Seungjae Kwak

Monday: Sequence Sudoku by Fred Stalder

Tuesday: All Even or All Odd Sudoku by Prasanna Seshadri

Wednesday: Diagonal Sudoku by Bastien Vial-Jaime

Thursday: Odd Even Stars Sudoku by Jakub Hrazdira

Friday: Extra Regions Sudoku by Tom Collyer

Daily League PDF's:

Week 16

Week 17

Rules for Sudoku

## Saturday 11 May 2013

### Daily League Sudoku #15: Difference Sudoku

This week I made a Difference Sudoku. I know I've made a lot of arithmetics-based variants. I think it's just what I'm most comfortable with. Just like I am most comfortable writing Loop genres when making puzzles.

I don't think this puzzle should be too hard. After last week an easier puzzle is probably appreciated. This puzzle has a simple opening and gets a bit harder in the middle, but nothing that should really break up the best solvers. Enjoy.

Recap of the last week:

Sunday: 2-Frame Sudoku by Seungjae Kwak

Monday: Arrow Skyscrapers Sudoku by Fred Stalder

Tuesday: Odd Sudoku with Descriptive Pairs by Prasanna Seshadri

Wednesday: Even Consecutive Sudokube by Bastien Vial-Jaime

Thursday: Odd Even Killer Sudoku by Christoph Seeliger

Friday: Jigsaw Sudoku by Jakub Hrazdira

Rules for Sudoku

In this Sudoku, numbers between two cells indicate the difference between the digits in those 2 cells.

I don't think this puzzle should be too hard. After last week an easier puzzle is probably appreciated. This puzzle has a simple opening and gets a bit harder in the middle, but nothing that should really break up the best solvers. Enjoy.

Recap of the last week:

Sunday: 2-Frame Sudoku by Seungjae Kwak

Monday: Arrow Skyscrapers Sudoku by Fred Stalder

Tuesday: Odd Sudoku with Descriptive Pairs by Prasanna Seshadri

Wednesday: Even Consecutive Sudokube by Bastien Vial-Jaime

Thursday: Odd Even Killer Sudoku by Christoph Seeliger

Friday: Jigsaw Sudoku by Jakub Hrazdira

Rules for Sudoku

In this Sudoku, numbers between two cells indicate the difference between the digits in those 2 cells.

## Saturday 4 May 2013

### Daily League Sudoku #14: Odd Even Frame Sudoku

Last week I didn't contribute a Sudoku to the Daily League, but this week I'm back. This week features another Frame Sudoku variant. As I'm a fan of most sudokus with sums and I'm pretty good at them, writing these generally comes pretty easy to me. It generally avoids the annoying problem of running out of solutions. I'm pretty sure I've seen this variant before. I'm just not able to remember where I have.

The last few Sudokus had been a bit easier than some of my others. I think this one will again be a bit more challenging, because it has a bit narrower solution path. I think I used the rules pretty well and it stays challenging till the end. I don't want to scare anyone off. I don't think there are any really hard deductions. I just expect slower times than in the previous few weeks. I hope you all enjoy it.

Recap of the last 2 weeks:

Sunday: Coded Sudoku by Seungjae Kwak

Monday: Odd Antiknight Sudoku by Jan Zverina

Tuesday: Anti-Diagonal and Fortress Sudoku by Prasanna Seshadri

Wednesday: Greater Than Sudoku by Bastien Vial-Jaime

Thursday: No Donkey Step Sudoku by Rishi Puri

Friday: Unique Sums Sudoku by Jakub Hrazdira

Saturday: Equal Sudoku by Christoph Seeliger

Sunday: Extra Regions Sudoku by Seungjae Kwak

Monday: Irregular Scattered Sudoku by Fred Stalder

Tuesday: Kropki Sudoku by Prasanna Seshadri

Wednesday: Figures Sudoku by Bastien Vial-Jaime

Thursday: Asterisk Sudoku by Rishi Puri

Friday: Frameless Sudoku by Jakub Hrazdira

Daily League PDF's:

Week 14

Week 15

Rules for Sudoku

In this Sudoku, the numbers on the outside indicate the sum of all odd digits or the sum of all even digits in the first 3 cells seen from that side. It can be that a clue indicates both the sum of all odd digits and the sum of all even digits.

The last few Sudokus had been a bit easier than some of my others. I think this one will again be a bit more challenging, because it has a bit narrower solution path. I think I used the rules pretty well and it stays challenging till the end. I don't want to scare anyone off. I don't think there are any really hard deductions. I just expect slower times than in the previous few weeks. I hope you all enjoy it.

Recap of the last 2 weeks:

Sunday: Coded Sudoku by Seungjae Kwak

Monday: Odd Antiknight Sudoku by Jan Zverina

Tuesday: Anti-Diagonal and Fortress Sudoku by Prasanna Seshadri

Wednesday: Greater Than Sudoku by Bastien Vial-Jaime

Thursday: No Donkey Step Sudoku by Rishi Puri

Friday: Unique Sums Sudoku by Jakub Hrazdira

Saturday: Equal Sudoku by Christoph Seeliger

Sunday: Extra Regions Sudoku by Seungjae Kwak

Monday: Irregular Scattered Sudoku by Fred Stalder

Tuesday: Kropki Sudoku by Prasanna Seshadri

Wednesday: Figures Sudoku by Bastien Vial-Jaime

Thursday: Asterisk Sudoku by Rishi Puri

Friday: Frameless Sudoku by Jakub Hrazdira

Daily League PDF's:

Week 14

Week 15

Rules for Sudoku

In this Sudoku, the numbers on the outside indicate the sum of all odd digits or the sum of all even digits in the first 3 cells seen from that side. It can be that a clue indicates both the sum of all odd digits and the sum of all even digits.

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