A molecular chemist from Harvard has been crowned the new Sudoku world champion.

Thomas Snyder, 27, runner-up in the first world championships last year, left spectators gasping at his solving speed.

Mr Snyder, whose day job involves investigating the substrates of DNA molecules, put his success down to his ability to scan a puzzle as a whole and visualise which cells to fill in first. He started solving puzzles aged four and always carries a selection to solve in spare moments.

He told The Times that he completed most Sudokus in about five minutes, but the fastest was finished in under two minutes – less than two seconds per cell. “I write down a number at the same time as solving the next cell to fill in.”

Describing himself as a “chronic multi-tasker”, he said that he liked to solve puzzles while watching films or cooking dinner.

Mr Snyder, who only took up competitive puzzling a couple of years ago, trained for this event by creating a new type of puzzle. He practised on a few hundred in the months before the world championships at the Top Hotel in Prague, attended by the Czech president.

Second in the event was Yuhei Kusui of Japan, third Peter Hudák of Slovakia, and fourth was David McNeill from Belfast, easily the best placing by a Briton in any similar competition. The 43-year-old lecturer at Queen’s University led the British team to a creditable 11th place out of 32 nations.

Mr McNeill, who carries out research in semi-conductor technology, said that the key to getting faster at Sudoku was always to use a timer.

“I use a Biro and try to limit myself to only two pencil marks when I am looking for numbers to fill in,” he said. He said that he solved most of his puzzles after his family had gone to bed.

Mr Snyder said that puzzle-solvers may have traces of obsessive compulsive disorder but that “all brilliant people have a touch of craziness”.

He is bringing out a book of new puzzles in America later this year but admitted that he was getting a little bored with the puzzle and did not want to be given any more Sudoku books as gifts.

Mr Snyder took five minutes to solve the Jigsaw Sudoku printed below. It is a simple variation of a classic Sudoku. See if you can beat his time – and remember that he did it on a podium with television cameras and 200 people watching him. (And he spent one minute checking his answer before handing it in.)

Amendment Tuesday, April 3

The online version of this story omitted the very important rules for solving this Jigsaw Sudoku. Our apologies.

The rule is: Fill in the numbers 1-9 in every column, row and every jigsaw shape. Any cell that has a round jigsaw border can contain only "round" numbers - that is, 3, 6, 8 or 9.

Under these rules this puzzle is correct and has only one solution as published. Again our apologies for the omission. If you don't believe me, believe Thomas Snyder whose comment is posted below.

Michael Harvey, T2 features editor

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