Dai-Vunk’s rematch was highly anticipated, but Kota Morinishi, 34, of Tokyo, a four-time world champion who works in information technology, took an early lead, fueled by a bag of candy his team captain once offered him.
Ms Dai had a rough start: in round 2 of 10, she made three mistakes on the same puzzle, or ‘broke’; She ended up erasing the whole thing and restarting it. While focusing on solving two broken puzzles in Round 3, she forgot one puzzle and did not complete it before time ran out.
Mr Vunk ended Round 3 with three minutes to spare – “Could have been better,” he said – putting him in first place, with Ms Dai in second.
Byron Calver, 38, a Toronto civil servant who sat next to Ms. Dai, was not happy with his actions. (His best result was fifth place, in 2010, but he had practiced too hard and was burned out, he said. Now, after a break, he tried to regain what he had lost: “Discovering your mortality by being bad at Sudoku , the Byron Calver story,” he said.) When asked how Round 4 went, he said, “It didn’t go.” These were Sudokus with arithmetic limitations. “I was great at math, I just forgot how to do Sudoku,” he said.
And at least once that day, in desperation, Mr. Calver resorted to a “wild split” – “split” being Sudoku-speak for “guess.” Normally it’s a calculated gamble with trial and error, exploring one of two clear paths presented by a partially completed puzzle. But in such an either-or game, only one path is correct. Mr. Calver’s split was more reckless, he said, “in that it arose more from blind hope in the absence of a clear path forward than from any well-founded expectation that progress would result.”