|John Denis Martin Nunn (born April 25, 1955) is an English chess player and mathematician.|
One of Englandīs strongest players, and once in the worldīs top ten, Nunn has won several individual gold medals at Chess Olympiads. He gained the International Grandmaster title in 1978 and in the same year was awarded his doctorate in mathematics by University of Oxford for a thesis on finite H-spaces. In 1989 he finished sixth in the inaugural (and only) World Cup, a series of tournaments in which the top 25 players in the world competed. His best performance in the World Chess Championship came in 1987, when he lost a playoff match against Lajos Portisch for a place in the Candidates Tournament.
As well as being a strong player, Nunn is regarded as one of the best contemporary authors of chess books. He has penned many volumes, including Secrets of Grandmaster Chess which won the British Chess Federation Book of the Year award in 1988 and John Nunnīs Best Games which took the award in 1995. He is the director of chess publishers Gambit Publications.
Nunn is also involved with chess problems, composing several examples and solving as part of the British team on several occasions. On this subject he wrote Solving in Style (1985). He won the World Chess Solving Championship in Halkidiki, Greece, in September 2004 and also made his final GM norm in problem solving. He is the third person ever to gain both over-the-board and solving GM titles (the others being Jonathan Mestel and Ram Soffer).
Since the mid-1990īs Nunn has been actively working on data mining from chess endgame tablebases. The offshoots of this ongoing work include the book Secrets Of Chess Endings and the series of books generically names Secrets Of ____ Endings, e.g. Secrets Of Pawnless Endings. These books include human-usable endgame strategies found by Nunn (and others) by extensive experimentation with tablebases, and new editions have come out and are due as more tablebases are created and tablebases are more deeply data-mined. Nunn is thus as of 2004 the foremost data miner of chess endgame tablebases. This work corresponds to the endgame part of the work of Berlekamp, Conway et al in dots-and-boxes, Hex and other games.
On the April 2005 FIDE list, Nunn had an Elo rating of 2617, making him number 98 in the world and Englandīs number four (behind Michael Adams, Nigel Short and Luke McShane).