The history of sudoku is a long story – or, at least, a long-distance story.
Magic squares date back to China and were generalised by the great Swiss mathematician Leonhard Euler. A hundred years ago, French newspapers published some puzzles that bear very considerable similarities to sudoku, if you squint. The birth and infancy of sudoku as they are generally known today is ascribed to Howard Garns, and it’s certainly true that there have been “Number Place” puzzles in Dell Pencil Puzzles and Word Games magazine since 1979. However, the puzzle only really grew up after it started being featured in the great Japanese puzzle company Nikoli’s monthly communications from 1984. Taking the analogy further, New Zealand’s Wayne Gould adopted the puzzle and introduced it back to the English-language mass market, starting with The Times of London in 2004. It has spread around the world from there.
Nevertheless, it’s probably fair to say that sudoku is largely considered a Japanese puzzle; certainly one of its Japanese names has broadly stuck, rightly or wrongly. This is the sense in which the ninth World Sudoku Championship represents something of a homecoming, for the individiual winner was Kota Morinishi of Japan, the first time the competition has been won by a Japanese solver. (Kota had finished second for each of the last thee years, so this does not come as a big surprise.) The individual results have been posted and the Independent has a report with a little colour about the play-offs. The team results will surely follow very soon.
Clearly Kota is in hot form and will be looking to do the double when the World Puzzle Championships start tomorrow, also in Croydon. Kota finished eighth in last year’s WPC, but also finished fourth in the World Puzzle Federation’s Puzzle GP series held over the year, so he’s definitely got a chance. Nobody has done the double before, though; the closest anybody has come is Dr. Thomas Snyder of Grandmaster Puzzles. Dr. Snyder won the World Sudoku Championship in 2007, 2008 and 2011, and finished second in the World Puzzle Championship in 2007 (and third in 2011). You have to imagine that Kota will be there or thereabouts in the puzzle championship, though there are a great many strong contenders trying to keep him from the title, not least his Japanese teammates.
Nevertheless, this site chooses to consider it a good sign for its prediction of Japan to win only its second ever team championship…
((Edited to add:)) While they’re not up on the web site yet, someone has posted a photo of the top of the team scoreboard. Congratulations to Japan for winning the team competition, by a narrow margin from Germany and China. As well as no individual ever having done the sudoku-and-puzzle double, no country has ever done it yet either – at least, until now!