IMAGINE you are a mover and shaker in the small but perfectly formed city of Lucca in Tuscany. Your city is famed for being walled, for having 100 splendid churches and for being the birthplace of Puccini. What more could you want? There can be only one answer: to host the world’s first Su Doku championship, of course.

So it was that 85 puzzle fanatics from 22 countries gathered in a Best Western Hotel outside Lucca yesterday. Their task was to complete 40 fiendishly fiendish puzzles against the clock and against each other. The prize for the speediest and most accurate? Well, no money as it happens, but copious glory in the ever-expanding puzzle fraternity.

By 9am yesterday they were limbering up in the lobby, flicking numbers on to grids with fingers so nimble you could hardly see them move. Nina Pell, a 18-year-old maths student and winner of The Times’ championship last year, looked dazed. She’d been practising for two hours a day over Cadbury’s Highlights, she confided. Her fellow Brit, Nick Deller, editor of Tough Puzzles magazine, admitted only to “several hours a day”. He did not look calm.

Team Turkey was quietly confident. “We have a prodigy,” announced their leader with a proud glance at the 17-year-old Mehmet Murat Sevim. Prodigy looked bashful.

Team Turkey were in special T-shirts. Team Philippines had blue satin bomber jackets, but it was a Japanese man called Tetsuya Nishio who grabbed the media’s attention. “The Godfather of Su Doku,” said the American team leader reverently. Mr Nishio thrust his biography into my hands and I read an impressive story of puzzle innovation and triumphs.

The puzzling, organised by the Italian puzzle magazine publisher Nonzero, began at 10am in a basement room where the contestants lined up pencil cases, rubbers and bananas. Their first task was to rattle off nine mini-puzzles in ten minutes. The first ten to complete them accurately would win bonus points, and after six minutes and seven seconds a Polish competitor held up the card that identified him to the organisers. Their entries were whipped into a room full of invigilators, and the competitors were presented with a further nine puzzles.

Here it got tricky, with 18 variations of Su Doku, and, as the morning wore on, confident faces crumpled, feet tapped with frustration and bananas were skinned and munched.

By the end of the afternoon the prodigy had reached 13th place and Nina and Nick were both placed honourably at numbers 32 and 34, though they were not high enough to make the cut of the final nine to play on today.

Tetsuya Nishio was in a tie-break for a place in the final with Michal Karwanski of Poland. Two Americans led: first Thomas Snyder, a preppy and impossibly useful 26-year-old Harvard chemistry student. Hot on his heels was Wei-Hwa Huang, a 30-year-old software engineer for Google in Silicon Valley, second only to the Turkish team leader in having attended 13 of the 14 world puzzle championships. He won four of them.

“What’s been important today is having puzzle experience and not just Su Doku experience,” Mr Snyder said. There you have it. Not a room full of anoraks or even Roy Croppers, just a room full of fanatics.

Today the finalists will battle for top place and Wayne Gould, the former Hong Kong judge who introduced Su Doku to The Times, will lead the awards ceremony. “I am astonished at what I have unleashed,” he said.

CORRECTION

Some editions have an error in the Samurai Su Doku in Books. In the middle of the top-centre box, situated in the bottom left-hand quadrant, the 5 should be a 2