SmartKit is featuring a new puzzle by Peter Grabarchuk called Strimko.  It’s a sudoku variation where, instead of the traditional square grid divided into sections, there’s a grid of circles connected by lines.  The circles that are connected by lines create the equivalent of the internal sections.

The Griddle has another sudoku variation up called Quad Clue Sudoku.  This variation features a six by six sudoku grid with four numbers at some of the grid intersection points.  These four numbers correspond to the four numbers in the four ajoining squares.  It’s another way of providing starting clues, without telling you exactly where they are.  Enjoy!

Tredoku is another sudoku variation.  In a tredoku puzzle, the grid is laid out in varrying three dimensional patterns.  The same rules still apply.  The same numbers can not appear in the same rows or columns or the same internal square.  In Tredoku, rows and columns continue even over 90 degree turns in the grid.

The main advantage here is that grid orientations are virtually endless.  And it’s a little bit neater than massively overlapping sudoku grids.  There’s currently a tredoku blog set up where you can go and try some of the puzzles.  Enjoy!

Wei-Hwa Huang won the second US Sudoku Championship this weekend beating reigning champ Tom Snyder by 26 seconds.  There is a nice little video that goes along with the Philadelphia Inquirer article in which a modest Wei-Hwa Huang says severa times that he does not expect to win.

A recent commenter posted on a new puzzle type called Suduro, billed as a Sudoku/Kakuro combo.  Readers of this blog should find Suduro familiar.  It is identical to my Circle Sum Sudoku puzzle.

On Blaine’s Puzzle Blog there was a sudoku variation called a mini-sudoku posted recently.  When I first heard the title, I thought it was just a sudoku puzzle with a smaller grid, but it’s more clever than that.  The puzzle is a 3X3 grid, one of the inner squares in a sudoku puzzle.  This means that the squares in the grid need to be filled with the digits 1-9.  The only clues that you have is the sum of the digits in L-shaped sections around the outside of the grid.

I didn’t catch this one when it first came up because of the name.  But it’s worth a closer look.

Over at onigame’s blog, there is a Penrose Sudoku posted.  The main trick to solving the puzzle seems to be discovering the row/column equivalents.  Go check it out and, please, post tips if you have them.

There’s a new sudoku variation over at The Griddle called Curve Doku.  The puzzle combines a killer sudoku with a greater-than sudoku.  It’s called Curve Doku because the two puzzles are connected by curves that also serve as blocks in the sudoku grid.

I got an email today about a web site dedicated to pentominoes.  Currently, the site is running a competition for readers to solve a pentomino sudoku.  It is similar to a standard sudoku, but the grid is made up of pentominoes and the numbers in each pentomino sum to 22.  Enjoy!

It’s still a few months away, but publicity has already started for the Sudoku National Championship in Philly on October 24-25.  The championship will include guest appearances by Will Shortz and Maki Kaji, credited as “the man who gave sudoku its name.”  (The creator of sudoku is actually American Howard Garns.)

It looks like they learned a lot in the first go around and have made a number of improvements for this years competition.  Most notable are help determining which level you belong in and a prize structure that awards more to the third place winner in the advanced level than the first place winner in the intermediate level.

A while back there was a post on Passion for Puzzles about a new kind of puzzle called KenKen puzzles.  The puzzle was featured on the Times Online site where a few puzzles were printed along with an article about the puzzles’ creator Tetsuya Miyamoto.  To be honest, I only skimmed the article.  It seemed to be more about the creator’s teaching philosophy than about puzzles.

KenKen puzzles are a variation of killer sudokus.  The layout is exactly the same.  The only difference is that the groups of boxes have not only a number, which in killer sudoku would represent the sum of the numbers in the boxes, but they also contain an arithmetic operator which tells you what to do with the numbers.  They need not only be sums.  They can be differences, products, or quotients.

Enjoy!

After coming off of my brief hiatus, I discover that the World Sudoku Championships have already come and gone.  Congratulations Thomas Snyder and the Czech Republic for their victories in the individual and team competitions respectively.

The site Sudoku World has an amusing little feature called “Safe For Work” sudoku.  The idea is similar to that of the boss key which was a feature of some old games.  The idea was that you could hit a button when your boss came by and look like you were doing something productive when you were really playing a game.  The same is true of the Safe For Work Sudoku.  It’s disguised to look like a spreadsheet that you’re working on.  Now, your boss will never know how many hours you spend playing Sudoku at work.

There was an article in Science Daily today about something called “color sudoku.”  Color sudoku is part of a research project at the University of Warwick regarding “Empriical Modeling.”  It’s not entirely clear to me what this is from the article, but the general idea is to look at the interactions between logic and perception.  This is where the color sudoku comes in.  In color sudoku, each digit is assigned a color and each square that has that digit in it is filled with that color.  The empty squares are filled with a combination of all of the colors for all of the possible digits that could go in that square.  This is intended to give you clues as to what should be there.  Darker colors, for example, will indicate more possibilities and, if the color in an empty square exactly matches that of a digit, you know which digit must go there.

While playing around with it, it was hard for me to see, at first, the advantage of the colors, but as more digits are filled in some patterns did begin to emerge.  Though I’m not sure if logic and perception ever actually met.  It’s an interesting idea and sudoku is a very accessible example, though likely not the best.

Wei-Hwa Huang who wrote the puzzles for the first US Sudoku Championship has posted two puzzles on his blog that were not included in the competition.  The two puzzles were rejected, it seems, because they were a little bit too tricky.  Try them out and see what you think.