Nov 01, 2010 - Claremont, CA -

The strong problem-solving skills of mathematics major Palmer Mebane '12 helped Team USA to emerge victorious at the 19th World Puzzle Championship held in Paprotnia, Poland, Oct 26-29. Up from second last year, the team is now 12-6-1 (gold, silver, bronze) in the 19 editions of the World Puzzle Championships.

Team USA, consisting of Mebane, Thomas Snyder (two-time world Sudoku champion), and veteran competitors Roger Barkan and Wei-Hwa Huang, was in first place most of the first two days, but slipped to second place in the last round, allowing a slight time advantage to the Japanese team. On the final day, the Americans dominated the team relay round, and survived a "no-notes physical Skyscraper Sudoku puzzle" to win the team championship. Japan placed second, and Germany third.

Huang and Snyder, both qualified for the eight-person individual playoffs, but were eliminated in the first round. Taro Arimatsu of Japan won first place, followed by Ulrich Voigt of Germany, Hideaki Jo of Japan, and Ko Okamoto of Japan. The Americans and Japanese each had three members who finished in the Top 10. Mebane, the rookie on the U.S. team, placed 19th--out of 105 competitors--in the individual round, a record-setting score for a first-timer. "They're all longtime veterans and I never expected to beat any of them," said Mebane of his teammates. "Personally, I was proud of my performance, and my team certainly approved."

"That Palmer performed so well during his first time at a world championship is a testament to his passion and talent for problem solving," said President Maria Klawe, who noted that Mebane was HMC's top finisher in the 2009 Putnam Mathematical Competition and the recipient of a sophomore mathematics prize last year. "He's a very talented mathematician."

Team USA had the top score during preliminary rounds 1 and 2, which consisted of puzzle types with which Mebane excelled, thus allowing him to contribute to the team's strong performance.

During the team finals, there were four individual puzzles--whose order and types were known--and one team puzzle. After each individual puzzle was solved, that team member could go to the team desk with a portion of the clues for the final Skyscraper Sudoku puzzle. Only the first person could work on the first puzzle at the start, and only when he was done could the second person start his, etc. The puzzle only became solvable when all team members got to the table with all of the clues, at which time the team worked together to solve it. The team that finished that final puzzle first won.

Mebane said, "The first puzzle turned out to be a major block for most teams, but our guy (Thomas Snyder) put it away quite quickly. Many minutes later, Japan's first solver got it, and not 30 seconds later our second (Wei-Hwa Huang) solved his. At this point we were a person ahead of all the teams. All four of the teams had someone cracking the second puzzle when our third guy (Roger Barkan) finished his, and that was when I started. I think Japan and Germany got to the third one while I was working, but that was it."

Mebane's puzzle was called Akari, a puzzle with which he is very familiar, having made many of them. So, he was quickly assigned to be the team member to do it. The puzzle contained some innovative logic but, undaunted, Mebane said he was able to "put it away very fast."

The Sudoku team puzzle was more challenging for Mebane, he admitted, but he said that he helped his team "by pointing out some obvious steps and by building the 'skyscrapers' the solution had to be presented as." With Sudoku veterans as teammates, Mebane wasn't feeling too much pressure. But there were some stressful times.

"The first tense moment was that we found a mistake about five minutes after I got to the table and had to clear the board," Mebane said. "The second is that just before we got to the cleanup portion of the puzzle, we heard some commotion and I saw the audience looking at a team table that was not ours, so I thought we couldn't win anymore. The third was that we finished, asked to be checked, and were told we had messed up. It turned out to be a simple error in cleanup though, so we got rid of some bad numbers we found, reinserted them and resubmitted to be declared correct and first place. This surprised all of us given the earlier commotion.

"I later learned that all four of our team members had finished our individual puzzles far faster than any other team did," said Mebane. "The first and third puzzles were particular bottlenecks, but they apparently weren't a problem to either Thomas or Roger. So we were two solvers ahead of every team when we started solving the Sudoku, and there was no catching up to us (even though we broke the Sudoku and had to restart). It took Japan about 10 minutes more than us. Germany took about 20 minutes more."

Goals of the World Puzzle Federation are:

• to provide the means for an international exchange of puzzle ideas;

• to stimulate innovations in the field of puzzles;

• to supervise the annual World Puzzle Championship (WPC) and other puzzle activities;

• to foster friendship among puzzle enthusiasts world-wide.

Palmer's puzzle blog.

Mebane's U.S. Puzzle Championship Finish

U.S. Puzzle Championship 2010