With most of my non-existent free time going towards WPC prep, here are two more puzzles that helped determine the US Sudoku Team. I'm posting my original version of the killer, which was tweaked for solvability on the test, leading to a "given" in R5C5 to shave many several minutes off the solve. Try it again if you want in the even more killer ( Read more... )

Congrats to the qualifiers for the US Sudoku team: Jonathan Rivet, Jason Zuffranieri, and new team member Joshua Zucker ( Read more... )

Here are all of my puzzles used in the recent US Sudoku Qualifier. While all are good to great puzzles, the "can't miss" ones are probably the Killer, Arrow, and Just One Cell Sudoku (warm-up on the first before tackling the harder second puzzle).

Classic Sudoku: Place the digits 1 through 9 into the empty cells in the grid (a single digit per ( Read more... )

The United States Sudoku Championship is next Saturday at 1 PM EDT and runs for roughly two and a half hours. Like the US Puzzle Championship, it is an online test to determine members of the US team at the upcoming World Championship in Eger, Hungary. Unlike the US Puzzle Championship, I will not be competing. Instead, I am one of the two test ( Read more... )

As with last year’s entry, I’m doing this awards style and keeping the categories from last year. Commenters are welcome to recommend other “awards” for the best or worst in puzzles.
( Read more... )

What if I didn't have a single clean subject today and just wanted to show ways I've been an idiot over the years while bringing up potential issues with grading and scoring? You might get an essay like this.

( Turn away if you cannot enjoy pure Schadenfreude )

About four weeks ago, a former sudoku champion rang a bell that cannot be unrung by claiming a fellow finalist was a cheater. While a lot of circumstantial evidence supported this case, no smoking gun was likely to be found from looking at video and photography from the event itself. Sudoku-related curiosities such as "unreasonable sticking ( Read more... )

(I'm sure an official announcement on philly.com will come soon, but an email signed by Will Shortz qualifies for me even with the many typos. Here, for the sudoku community - whether advanced, intermediate, or beginner - is finally some justice; nothing can fully restore the finals, but this is something.)

Dear Thomas ( Read more... )

TIME.com was following Wei-Hwa and me at the recent Sudoku National Championship and the video piece was just released. Aside from some minor factual flaws (I turned in my final puzzle at ~4:14, not ~7:30 for example), it captures the whole championship - even Eugene - really well. (Note: I'm not getting the embedded video to play right from lj ( Read more... )

Sudoku contest competitor to be retested - so, maybe someone found Eugene after all (or his not showing will make a choice easier?). This could get weird and I'm not sure what this extra step means in terms of how the investigation is leaning. Also of note, Phil Irwin from the chess community is the first to publicly associate the chess "player" ( Read more... )