Some say imitation is the sincerest form of flattery. This puzzle resulted as I was playing around the construction space of one of my favorite puzzles from the BIST which used the same cage and sixteen given pattern. Here the first few digits go in the same, but I added my own calling card after that and the remainder of the puzzle solves pretty differently and is harder than the version we saw. I hope you enjoy this Irregular Sudoku which I wrote from China before the playoffs.

Rules: Place a digit from one to nine into each cell so that no digit repeats in any row, column, or bold region.

A funny thing happened after winning my third world sudoku championship in Hungary last year. I didn't get one interview. Not a single reporter on site. Not a single email or phone query when I got back home. So for those wondering why I never linked to any new video of me being quirky after my most dominant sudoku tournament win against the strongest field yet, that is why.

Well, I expected BIST 2012 to be much different. With the Beijing Media Network being a primary sponsor, it was obvious interviews would happen. Two cameras got me at the airport as I exited customs. More got me on the daily excursion. I got pulled out of my hotel room while relaxing pre-opening ceremony for an interview. Then there was a press conference run during the start of dinner where six solvers (the top four from last year who would again qualify as the top four this year and two Chinese solvers) were asked questions. When the instruction meeting later was over they wanted video of me offering tips to the youngest Chinese competitor, and shots of me solving puzzles. During the competition, it felt like all the 10 minute breaks became five, because I certainly had to share the world an update on that last round. And when I wanted to go hide after one of my worst playoff performances in memory, I instead stayed and grinned and gave another closing set of answers talking about how beautiful the puzzles were, to highlight Chen Cen's (and others?) work to make a great tournament. Given how poorly I performed, I bet almost none of this footage was used. Still, there are often open shot rolls given out as B-reel footage for other agencies that might run a story. I found such footage (I'm most of the last 90 seconds) that comes close to a BINGO on the Snyder Sudoku footage game card, what with excessive hand motions, awkward shots of me looking at nothing in particular, the "you know" problem, the stuttering, and my favorite, an odd but edgy quote - here it is equating sudoku with other addictive drugs (cleaned of above problems):

"If you're having a stressful day you can take a 10 minute break and go do a puzzle. Some people may use something else for their relaxation: smoke a cigarette, get a drink, .... I solve a puzzle. So, maybe I'm a strange person in that way but it is relaxing and fun."

I find myself pretty funny when I'm jet-lagged and trying to make sudoku sound interesting. Maybe you will too.

ETA: Here is one of the better print pieces - at least in that it highlights some of the puzzles as I was trying to do (this is from after the semi-final): "Most Sudoku puzzles are designed by computers, which are not really interesting... if you make poetry by computer, it would not be interesting poetry either. But these have very artistic, logical themes."

Around 2007, when I first saw Blackout Sudoku in GAMES magazine, I must have channeled my inner Roger Ebert when my reaction was "I hated, hated, hated this variation". I've never sought them out to solve because they are not fun and I like to enjoy puzzles from time to time. It runs too counter to normal thinking, and is far too easy to make a mistake when you are actually, you know, trying to solve with sudoku approaches.

Five years later, after botching the Blackout in a competition round with >15 minutes of time to do just it, I managed to also botch the Blackout in the semi-finals with >15 minutes of time to do just it. Not a good year for me. With that puzzle worth slightly more points than others people stumbled on, I fell to near the bottom of the all but one done group. Add that to forgetting to pack pencil leads, and not reading the instructions before arriving here which would have led me to bring highlighters for the Windmill Sudoku, and it is clear to me that my focus on work and puzzle construction is really affecting my puzzle competition as I simply have no time or energy to do the right preparation.

Jan had probably the best semi-final performance by many minutes. Even if I'd cleanly gotten the Blackout done in the first of three tries, I would have been behind by 3 minutes. Unfortunately, he transposed digits in one of the puzzles and lost all time bonus and 3 positions to fall to 4th. Instead, the finalists are Jakub Ondrousek and Kota Morinishi. I wish them luck in the finals starting in a couple hours.

ETA: And Kota takes the title in about 24 minutes of solving (and 6 minutes of grading). The two competitors were tied after the first puzzle but Kota did good work on the second classic sudoku (seeing a column 4 deduction rapidly from spotting what I'd call a nontrivial hidden pair) and built a large lead on Jakub. Even when Kota slightly stumbled and needed to restart the fifth Diagonal puzzle, Kota was still about 2-3 minutes ahead. His solving style was very interesting to watch (I'd only seen it briefly while he was finishing in Eger last fall) and his manual dexterity at writing numbers is far better than mine. Congratulations to the new champion.

The puzzles are again tremendous; my performance, not so much. When you submit a sprint round early but forget to look at the puzzle on the first page, you are certainly making boneheaded errors. Repeat this sort of thing all day with at least one broken puzzle in each round and you get the kind of average performance I've been having. Fortunately, my average is still good for ~4th, and I will have a shot tomorrow in the Semifinals. Jakub, Jan, and Kota round out the top group, all the usual suspects, with Hideaki, Tiit, Florian, and Yuhei sitting another 10% back in 5th through 8th. It will be a dramatic race tomorrow I am sure.

As this entry is posting, I'm in China at the 2012 Beijing International Sudoku Tournament. I'm hoping to have another fun trip, even though none of my US, Canadian, UK, or Indian puzzle friends will be at the tournament this year making for much less interesting meal conversation. To be completely honest, my tournament expectations aren't too high. Since I won my third world championship six months ago and started my new job, I haven't had too much time to "train" at sudoku and my LMI sudoku test performances have been really slipping. Being out of practice means losing "sprint" speed mostly, and last year's playoffs were entirely sprint puzzles. So my hope is to finish as good as last year at the BIST (4th or better), but I think I only have an outside shot of winning. Jan, Jakub, Tiit, and Kota (if not others) all probably have a better chance than me at the moment. Best of luck and skill to all the competitors.

I wrote some sudoku for the recent UK Open Sudoku Championship and this week's entry is another one of them. Enjoy!

Rules: Place a digit from one to nine into each cell so that no digit repeats in any row, column, or bold 3x3 box. In addition, the digits in each "thermometer"-shaped region must be strictly increasing along any marked path from the circular bulb to an end.

I wrote some sudoku for the recent UK Open Sudoku Championship and this week's entry is one of them. Enjoy!

Rules: Enter a digit from 1 to 9 into each cell so that no digit repeats in any row, column, or 3x3 region. Digits in the circled cells represent the sum of the digits along the path that each arrow travels. Digits can repeat within an arrow sum, provided this does not violate the standard sudoku rules.

After a string of sudoku puzzles, here is something slightly different.

Rules: Place stars into some cells in the grid so that each row, column, and region contains exactly two stars. Stars cannot be placed in adjacent cells, not even diagonally. (The example uses just one star.)

Example:


Puzzle:

While this might look like another interesting classic sudoku from my new book "The Art of Sudoku", you'll have a lot more success treating it as the nonconsecutive sudoku that it is. Enjoy.

Rules: Place a single digit from 1 to 9 into each cell so that no digit repeats in any row, column, or bold 3x3 region. Consecutive digits (ie 3 and 4) cannot appear in any pair of horizontally or vertically adjacent cells.

While I thought it might take a couple weeks to get listed online, I found that my latest book The Art Of Sudoku is already available for order. Feel free to get it at Barnes and Noble or at Amazon.com. I should be listed in UK, European and Australian sites soon too.

This week's Friday Puzzle will complete a 6-puzzle sampler I had in mind for this work (here is a pdf of the whole set laid out as in the book). The 6 puzzles span a range of difficulties and showcase very different kinds of themes I used in the book, including patterns in the digits, themes using the properties of the numbers like even/odd, large/small, or increasing/decreasing series, geometric patterns, and logical themes. Today's puzzles, #45 and #60, showcase some unusual given patterns that lead to good average difficulty puzzles.

Rules: Place a single digit from 1 to 9 into each cell so that no digit repeats in any row, column, or bold 3x3 region.

#45


#60

Until a book is available for sale, it is hard to celebrate the work that went into it. But I find there are always tantalizing moments of excitement as the finished product starts to come together.

Last week, for example, I got to see the cover artwork of a book I spent most of early 2011 working on with Mike Selinker, making this work feel much more real than it used to. The cover is still not public, even if the book's identity and possible (but not probable) release date is listed now. Another book, which is either about sudoku or goldfish, is advancing now too.

Well, today I discovered the "new book smell" is just as exciting when you are the publisher. I've been working on this classic sudoku book since January 2012, so the battle of creativity is much fresher in my mind. I finally submitted my files to the printer over the weekend. It will take a little time to show up for sale online at usual places like Amazon and B&N, but I can now say for certain that you too can be holding The Art of Sudoku in May. Until then, I can only tease you with this image of the (pretentious?) author/publisher and the first copy of his work. The book is hiding my smile!