The Dai-Vunk rematch was highly anticipated, but Kota Morinishi, 34, of Tokyo, a four-time world champion who works in information technology, quickly took the lead, fueled by a bag of candy always offered by the captain of his team.
Ms. Dai had a rough start: in the second round of ten, she made mistakes or “broke” the same puzzle three times; finally it cleared everything and rebooted. In the third round, while she was focused on fixing two broken puzzles, she forgot one puzzle and didn’t complete it before time ran out.
Mr Vunk finished the third round with three minutes to spare – “It could have been better,” he said – putting him in first place, with Ms Dai in second place.
Byron Calver, 38, a Toronto civil servant sitting next to Ms. Dai, was not pleased with her performance. (His best finish was fifth, in 2010, but he overtrained and burned out, he said. Now, after a break, he was trying to reclaim what he’d lost: “Finding out your mortality by being bad at Sudoku, the Byron Calver,” he said.) When asked how the fourth round went, he replied, “It didn’t go.” It was of Sudokus with arithmetic constraints. “I did really well in math, I just forgot how to do Sudoku,” he said.
And at least once that day, in desperation, Mr. Calver resorted to a “wild fork” – “fork” being Sudoku parlance for “guess.” Typically, this is an estimate calculated by trial and error, exploring one of two clear paths presented by a partially completed puzzle. But in such a bet, only one way is correct. Mr. Calver’s bifurcation was more reckless, he said, “in that it was driven more by blind hope in the absence of a clear path forward than by a well-founded expectation of progress.” .