TVC XVII Practise: Part 1

This is the first selection of practise puzzles for the upcoming TVC XVII. I only came aware this was starting again today, so I'm trying to get all puzzles out by Friday. This post will feature the first five puzzles.

The first puzzle is a Peers Tapa. I like the idea of this variant. I always enjoy Tapas that have the same sum in symmetrical clues. This variant forces that. The puzzle turned out reasonably well. It's one of the easier practise puzzles.
The second puzzle is a Tapa Skyscrapers. The variant can drive a lot of the puzzle, so I tend to just place some random, but nice looking, Tapa clues and make the variant drive the rest of the puzzle. I think it worked out well in this puzzle. It's not an overly hard puzzle, but you have to understand how to use the variant.
The third puzzle is a Knapp Daneben Tapa. I always have trouble with 1s turning into 0s when designing Knapp Daneben puzzles. I tried to avoid the issue as much as possible. My personal goal when designing Knapp Daneben puzzles is always to try to only use valid Tapa clues and not use combinations of digits in a cell that would not be allowed in a normal Tapa.
The fourth puzzle is an Outside Tapa. The first Outside Tapa I wrote I used a lot more Tapa clues, but I went for a lower number of clues this time and have the variant drive the solve a bit more. It turns out that using more equal symbols reduces the need for clues. I think it turned out well. This is probably the hardest puzzle in this set.
The fifth puzzle is a Tapa Magic. I'm not that much a fan of this variant. I always feel I have to use too many clues, because the restrictions won't allow it to be unique otherwise. It's still a nice puzzle and shows some of the tricks in this variant.

I hope these are helpful. Enjoy.

[Edit: Tapa Skyscrapers fixed.]

Puzzles can be found below.

TVC XVII Practise: Introduction

It seems 2016 is again a Tapa Variations Contest and Classic Tapa Contest year. That means that I'll actually have to defend my Tapa Master title I won in 2013 instead of the coasting on the honour without little effort. The CTC will run daily over 50 days from the 2nd of January 2016 till the 22nd of February 2016. The TVC will run in four contests over weekends between the 2nd of January 2016 and the 22nd of February 2016  The first of these contests, TVC XVII, will run from the 2nd of January 2016 till the 4th of January 2016.

TVC XVII will contain 10 variations. These variations are Alternative Tapa, Tapa with Borders, TAPA LOGIC, Peers Tapa, Tapa Skyscrapers, Make Room For Tapa, Tapa Star, Knapp Daneben Tapa, Outside Tapa and Tapa Magic. These are all variations that have previously appeared in other TVCs. So for practise you can check out older TVC's. In this post I will post the puzzles I shared before as practise for older TVCs. I will also be posting new examples for all these type in other posts. I hope they will all be useful in preparation. But not too much as I'd like to be the first to successfully defend a Tapa Master title.

Puzzles can be found below.

Daily League #53: Quad Division Sudoku

This is the fourth and last Sudoku in the 'Quad Sudoku' series. It's as far as I know a new variant. I wish I could check somewhere what variants have been done already. I though it would be nice to have a variant where the four cells were treated as two two-digit numbers. I considered turning the Diagonal Difference puzzle from instructionless round of the last WPC into a Sudoku, but I had already made a Quad puzzle with differences. Then I figured I could do something similar with division.
I just started playing around with a few placements and I noticed that the clues carry a lot of impact. They give you a lot of information and you get placements pretty quick. So I figured it should be possible to make one without any givens. I always enjoy trying to turn out Sudokus without any givens, which most people doing my Daily League puzzles must have noticed. This puzzle had an opening constructed pretty quickly. The problem of course was to get it unique with only valid clues. I had a few puzzles that were close but I couldn't get any valid clues in anymore to make it unique. After a few tries, this puzzle came out. I don't think it's overly hard, but it does involve a bit of careful calculations to make sure you don't make any errors. There's very little chance to track back.

Rules for Sudoku

In this Sudoku, a number on a grid point indicates the result of dividing the two-digit number formed by the top two digits by the two-digit number formed by the bottom two digits. Both two-digit numbers have to be read from left to right.

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Daily League #52: Quad Max Sudoku

This is the third puzzle in the 'Quad Sudoku' series. This time once again a common variant. I picked this type as it's not an arithmetic variant and many of the Quad variants are arithmetic in nature. It's also a type that I enjoy solving.
In the design I wanted to see how far I could get with just Quad Max clues. I knew that eventually had to use givens as there is no way to differentiate between 1s and 2s with these clues. I think the design worked out well. The puzzle in the end has four givens. One of them is not necessary for uniqueness, but I wanted to keep the symmetry and it didn't ruin the solving path. The last few digits are a bit tricky, but I thought it was okay with so few digits remaining.

Rules for Sudoku 

In this Sudoku, an arrow on a grid point points to the highest digit in the four cells around it. Digits may repeat around an arrow, but the highest digit is always unique.

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Daily League #51: Quad No Difference Sudoku

This is the second puzzle in the 'Quad' Sudoku series. As far as I'm aware this is a new variant. It's the first puzzle I wrote for this series. I just thought it would be better to open the series with something more common. I thought the variant worked pretty nicely.
The design was a bit tricky. I had a different layout in mind, but I couldn't find a way to get that layout unique without giving digits around a clue. That was something I was trying to avoid as I think these Quad Sudokus look nicer when there are no digits given around the Quad clues. I changed the layout a bit in the left top and right bottom nonet. Originally the right bottom nonet was to get a Quad clue as well, but there was no way to force the 5 with such a clue. I needed that 5 for uniqueness. I still think it's a nice looking puzzle and it should be a good solve.

Rules for Sudoku

In this Sudoku, a clue given on a grid point indicates that no two of the four digits around it have this difference. E.g. a 3 clue indicates that no two of the four digits around it have a difference of 3.



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Daily League #50: Quadruple Sudoku

This month's theme is Quads. They will all be variants that with clues on grid points, that give information about the four cells around it. This set will contain two known variants and two new variants, as far as I'm aware. The choice for this theme came because I had an idea for a variant. I made a Sudoku with it and I think it turned out nicely. I figured it would make a good theme as there are many variants that use such a clue.
The first Sudoku is the most common variant. It's a variant I've written once before, but never for the Daily League. It's what I consider a classic variant, because there are no alternative clues in it. I wanted to make one without any overlapping clues. It turned out nicely in my mind.

Rules for Sudoku

In this Sudoku digits given on a grid point indicate the digits in the four cells around it.

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Daily League #49: Descriptive Pairs or Next To Nine Sudoku

This is the fifth puzzle in my 'A or B Sudoku' series. It is a combination of Descriptive Pairs Sudoku and Next To Nine Sudoku. I thought I might be able to combine these genres as they both use two digits for clues.
These are two types that suit my design style a bit more, because I like designing Sudokus without any givens in the grid. It was a bit hard to find a good opening, so I went for a relatively obvious opening clue. The opening is pretty narrow and it takes a while for the solve to open up a bit. I'm pretty happy how it turned out. I thought the two types work well together.

Rules for Sudoku

In this Sudoku each pair of digits is either a Descriptive Pairs Sudoku clue or a Next To Nine Sudoku clue. In a Descriptive Pairs Sudoku clue, one of the digits indicates the position of the other digit in that row or column when looking from that side. A Next To Nine Sudoku clue indicates the two digits that border the 9 in that row or column. Different clues can conform to different rules.

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Daily League #48: Edge Sums or Frame Sudoku

This is the fourth puzzle in my 'A or B Sudoku' series. It's a combination between Edge Sums and Frame Sudoku.

These two type are pretty similar. One uses the sum of the first two cells and the other the sum of the first three cells. I find both types fun to solve, but I do think they get the same pretty fast. There's a few variations on them that make them a bit more interesting, like Hi-Lo Frame Sudoku and Frameless Sudoku. I thought the combination of the two and three cell sums might make it more interesting. I am happy with how the puzzle turned out, especially getting the ending to work with so few clues was fun to figure out. Hope you enjoy it too.

Rules for Sudoku

In this Sudoku the numbers on the outside indicate the sum of the digits in the first two or first three cells seen in that row or column from that direction. The number of digits can differ between different sums.

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Puzzle #169: Fortress Sudoku

For his last two puzzles for the Daily League, Tom Collyer has been playing around with the same layout in his Extra Region and Clone Sudoku and his Very Odd Sudoku. This second puzzle can be solved under a second rule. After having solved it both ways, I tried solving it under a few other rules that might be presented that way. None of them worked. But I found that solving it under Fortress Sudoku rules lead to some interesting deductions by removing a few of the givens. So with that opening, I started playing around a bit what givens would make it unique. This is the result. I think it turned out nicely.

Rules of Sudoku

In this Sudoku digits in grey cells are larger than all orthogonally adjacent white cells.

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Daily League #47: Palindrome Or Rising Sudoku

Here is the third puzzle in my 'A or B Sudoku' series. This time it is a combination between Palindrome Sudoku and Rising Sudoku. Rising Sudoku might be a bit unfamiliar. It's basically a Thermometer Sudoku without a bulb to indicate the low point of the line. I saw them more often years ago, but I think now Thermometer Sudoku has become a bit more the go-to genre.
I wasn't sure if this combination would work very well. It was a bit hard to figure out how to get a start in this Sudoku, without giving away too many givens. The construction was a bit troublesome as I ran into situations without a solution far too often. The problem was that a lot of areas wouldn't resolve themselves early in the solve and by the time they did, there would be a contradiction with clues I had laid out in the meantime. In the end, I think the puzzle worked out nicely.

Rules of Sudoku

In this Sudoku a grey line is either a Palindrome Sudoku or a Rising Sudoku clue. In a Palindrome Sudoku clue the digits along the grey line form a Palindromic sequence; the sequence can be read the same from either end. In a Rising Sudoku clue, the digits form a rising sequence from one end to the other. This sequence does not have to be an arithmetic sequence. Different grey lines can conform to different rules.

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Daily League #46: All Odd Or All Even Sudoku

This is the second puzzle in my 'A or B Sudoku' series. This time it's a combination of Odd and Even Sudoku.

This combination has been done before, but I've always enjoyed solving them. I generally like puzzles with parity. I used the same layout for this puzzle as one of my earlier puzzles, namely my Renban Sudoku (and in a sense my Arrow Sudoku). I thought this layout would work well for this genre and I was right. I found some interesting interactions in this layout. These interactions might lead to some harder logic, but they should be fun to figure out.

Rules for Sudoku

In this Sudoku grey cells within a single marked 3 by 3 area are either all odd or all even. This can differ between different areas.

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Daily League #45: Clone Or Extra Region Sudoku

After a Daily League hiatus of over a year, I've written a number of Sudokus again. I'm planning on keeping it up for a while.

For this month, all my Sudokus will fall in a particular theme. This theme is "A or B Sudoku". This means that clues for two different genres appear in the Sudoku and it's up to you to figure out which clues are part of which genre. The reason for this theme is that one of my favourite Sudokus I have written for the Daily League was my Ace Sudoku. I really enjoyed writing that puzzle, playing around with getting the different rules having to be used in different areas. I think it's a fun solve personally. So I started playing around with different rules that are normally presented in the same way. When I had a few out, I decided I would be posting them in the Daily League.
The first puzzle is a combination of Clone and Extra Region. I first searched for a nice layout that allowed for multiple 9 cell areas that don't touch each other. The three I-shaped regions look nice and work well together. I think the combination worked out well, but can probably be improved on a bit.

Rules for Sudoku

In this Sudoku each grey area is either an Extra Region Sudoku or a Clone Sudoku clue. A Extra Region Sudoku clue contains the digits 1~9 exactly once. A Clone Sudoku clue has the exact same digits in the same place as one or more of the other grey areas, without rotation or reflection. Different grey areas can obey different rules.

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Polish Puzzle Championship 2015

This weekend were the Polish Sudoku and Puzzle Championships. I was one of the puzzle contributors and test-solved all puzzles for the championship (and a few more that didn't appear). Both events were won by Jan Mrozowski. You can find all puzzles at the following links: Sudoku and Puzzle. (As a small note, there is a printing error in Round 4 (my puzzles). In the larger Summon puzzle, the 3 clue at the bottom should be a 9).

This post will contain all my puzzles that were used at the championships. I used a similar structure to my round as last year, with two puzzles of each type. I tried to get a good mix of different genres, both familiar and unfamiliar. I didn't use any of the types I used last year to keep mixing it up. There's enough genres to choose from, so it seems a bit weird to repeat a genre. I think it worked out well and would love to hear some feedback from the competitors.

Puzzles can be found below.

Puzzle #168: Statue Park, Summon

These three puzzles were originally written for the Polish Puzzle Championships being held the upcoming weekend. I aimed to write a similar set as last year, with 2 puzzles per genre. I again wrote 20 puzzles, but the test times were a bit long for a 60 minute round. I cut the Statue Park puzzles, because they didn't allow for reflection and that was the type that most likely would trip people up from that because of that.
This Summon puzzle was the original harder puzzle, but they both tested too long for their intention. So the smaller puzzle became the harder and I added a smaller puzzle to the set. I've started to like this genre better, but I still feel they somehow stay hard to solve. I think it's because it doesn't have a natural flow and it's sometimes hard to know where to look next. The logic is always solid, but it's easy to get stuck none-the-less.

Puzzles can be found below.

2014 Slovak Puzzle Championships

While going through my puzzle files, I came across the Slovak Championships folder. I realised I had never shared these puzzles on my blog. So I figured I might as well share them now.
I was contacted by Zuzanna Hromcova to write puzzles for their championship. We were given a number of categories to write puzzles in. One of the categories was non-grid puzzles, for which I provided three different genres; namely ABC Decoder, Dice and Mastermind. Dice and ABC Decoder are types I enjoy writing; Mastermind I didn't have that much experience with. But it was something I'd like to give a go.
The other categories I picked were Latin Squares and Division puzzles. For each type we had to write a standard genre and a variant on the genre. I picked Skyscrapers, with Haido as the variant. I like Skyscrapers and I thought Haido still had part of the Skyscraper logic, but used differently enough to make it not like solving four skyscraper puzzles.
For the Division set I picked ABCD Division, with Sum Division as the variant. It's a type I have seen a lot when I first started puzzling, but I haven't really seen it much since. I thought sums was an obvious variant, but I haven't really seen it this way much. I have seen a similar variant where the grid has to be divided into a complete set of pentominoes, but not really without this restriction.

I tried to put a bit of theming in the non-grid puzzles. I wrote a few nine digit ABC Decoders for the 2014 24 hour championships, and I thought that was a good size to use in a championship. The letters spell out THE SLOVAK, which was the nicest way I could use nine different letters to write something Slovakia related. I found some words with opposite meanings in the letter set, so I used those. I think it turned out well.
I used a similar opposites theme for the Dice puzzle, with an addition of 5 words to make it unique. I think not all words are necessary for uniqueness, but it solves pretty well this way.
The first Mastermind puzzle looks really nice, with a sequence of numbers and only white circles it solves really nicely. The second one was merely an attempt to construct a nice logical 5 digit puzzle.

I thought both Skyscrapers puzzles turned out nicely. The first puzzle uses three 4s and three 5s. The second puzzle has a trio of the same digit on each side. Of course I couldn't use four different digits as these are the only three digits you can have three of the same clue on the same side in this size.
I find it hard to theme Haido puzzles as the clues are a bit limited, but they both have nice logical paths.

The first time I saw an ABCD puzzle this way was at a Dutch championship. It was a bit of a surprise then. I wrote a similar puzzle for puzzlepicnic once and I thought it would be fun to include one for the championship. The ABCDE puzzle is a standard layout and I think it solves well.
The sum puzzles were a bit hard to work out openings at first as there are so many ways to reach the sums. So I went with obvious opening digits for both puzzles to then work back to more ambiguous digits towards the end. I think they both turned out well.

Puzzles can be found below.

UKPA Open Team Round: Hole in the Wall

It's been a long time since I actually posted something. I haven't really gotten around to writing puzzles for my blog in ages. I took a break for a while. I have been getting back to writing puzzles a bit, but those have mostly been going out to other places. Some of them might appear again on this blog and others might be seen in other places online.

This post will contain puzzles I wrote as a team round for the UKPA Open. It wasn't an official round. It was more t give the puzzlers some practise in team solving while the organisers finished the final checking. I haven't much idea on the results. I wrote the round in two days and sent it in to Liane two days before the Championship was held; just in time for them to get it ready to be solved. I didn't have time to get it tested, but I hope people still enjoyed it.

The structure of the round is pretty simple. There are six 6 by 6 puzzles and six 10 by 10 puzzles. You are not given the rules of each specific puzzle, but are instead provided with six sets of rules under which each puzzle could be solved. You have to match the puzzles to the rules, so that each rule is used once for each size. Additionally, all 10 by 10 puzzles have a marked 6x6 hole, in which the clues of one of the 6 by 6 puzzles have to be placed, without reflection or rotation. Each 6 by 6 grid can only be placed in one of the 10 by 10 grids. The rules for 6 by 6 puzzle won't necessarily match the rules for the 10 by 10 puzzle it is placed in.

Puzzles found below or through the following link.