John Denis Martin Nunn (born 25 April 1955 in London) is an English chess grandmaster, a three-time world champion in chess problem solving, a chess writer and publisher, and a mathematician. He is one of England's strongest chess players and once was in the world's top ten.
As a junior, he showed a prodigious talent for the game and in 1967, at twelve years of age, he won the British under-14 Championship. At fourteen, he was London Under-18 Champion for the 1969/70 season and less than a year later, at just fifteen years of age, he proceeded to Oriel College, Oxford, to study mathematics. At the time, he was Oxford's youngest undergraduate since Cardinal Wolsey in 1520. Graduating in 1973, he went on to gain his doctorate in 1978 with a thesis on finite H-spaces (titled "Some Problems in Algebraic Topology"), and remained at Oxford University as a mathematics lecturer until 1981, when he became a professional chess player.
In 1975, he became the European Junior Champion. He gained the Grandmaster title in 1978 and was British champion in 1980. Nunn has twice won individual gold medals at Chess Olympiads. In 1989, he finished sixth in the inaugural 'World Cup', a series of tournaments in which the top 25 players in the world competed. His best performance in the World Chess Championship cycle came in 1987, when he lost a playoff match against Lajos Portisch for a place in the Candidates Tournament. He won the prestigious Hoogovens tournament (held annually in Wijk aan Zee) in 1982, 1990 and 1991.
He achieved his highest Elo rating of 2630 in January 1995. Six years earlier, in January 1989, his then rating of 2620 was high enough to elevate him into the world's top ten, where he shared ninth place. This was close to the peak of the English chess boom and there were two English players above him on the list; Nigel Short (world number three, 2650) and Jonathan Speelman (world number five, 2640). Nunn has now retired from serious tournament play and, until he resurfaced as a player in two Veterans events in 2014 and 2015, had not played a FIDE rated game since August 2006; however, he has been active in the ECF rapid play.
As well as being a strong player, Nunn is regarded as one of the best contemporary authors of chess books. He has penned many books, including Secrets of Grandmaster Chess which won the British Chess Federation Book of the Year award in 1988 and John Nunn's Best Games which took the award in 1995. He is the director of chess publishers Gambit Publications. Chess historian Edward Winter has written of him:
A polymath, Nunn has written authoritative monographs on openings, endings and compositions, as well as annotated games collections and autobiographical volumes. As an annotator he is equally at home presenting lucid prose descriptions for the relative novice and analysis of extreme depth for the expert.
In a 2010 interview, Magnus Carlsen, explaining why he thought extreme intelligence could actually prove to be a hindrance to one's chess career, cited as an example Nunn's never having captured the World Chess Championship title:
He has so incredibly much in his head. Simply too much. His enormous powers of understanding and his constant thirst for knowledge distracted him from chess.
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. There were further wins of the World Championship in 2007 and in 2010. He is the third person ever to gain both over-the-board and solving GM titles (the others being Jonathan Mestel and Ram Soffer; Bojan Vučković has been the fourth since 2008).
Since the mid-1990s, Nunn has been engaged in data mining from chess endgame tablebases. The products of this work include the books Secrets Of Rook Endings, Secrets of Minor-Piece Endings, and 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.
Nunn finished third in the World Senior Chess Championship (over-50 section) of 2014 in Katerini, Greece, and second in the European Senior Chess Championship (over-50) of 2015 in Eretria, Greece.
Coincident with a reduction in his over-the-board chess, Nunn has developed a great passion and understanding for astronomy, a hobby he shares with ex-world chess champion Viswanathan Anand. Nunn regards himself as a keen amateur in the field, but the various articles and lectures featured by Chessbase News show that Nunn's knowledge of the topic is quite considerable.
He is married to Petra Fink-Nunn, a German chess player with the title Woman FIDE Master. They have a son, Michael.
- Jacob Øst-Hansen vs John Nunn, World Student Olympiad, Teesside 1974, Vienna Game, 0–1: the Frankenstein-Dracula Variation of the Vienna Game regularly provides swashbuckling play and Nunn's game with Jacob Øst-Hansen at Teesside 1974, was no exception. The latter part of the game was played in a frantic time scramble, with Nunn sacrificing pieces to bring the enemy king into the open and deliver checkmate.
- Alexander Beliavsky vs John Nunn 1985, Wijk Aan Zee 1985, King's Indian, Samisch Variation, 0–1: this game is sometimes referred to as "Nunn's Immortal", and was included in the book The Mammoth Book Of The World's Greatest Chess Games (Robinson Publishing, 2010). In his book Winning Chess Brilliancies, Yasser Seirawan called this game the best of the 1980s.
- Seirawan, Yasser, Winning Chess Brilliancies, Microsoft Press, 1995.
- 101 Brilliant Chess Miniatures (2000), Gambit Publications. ISBN 1-901983-16-1.
- Beating the Sicilian 3 (1995, with Joe Gallagher), Henry Holt & Co. ISBN 0-8050-4227-X.
- The Benoni for the Tournament Player (1982), Batsford. ISBN 9780713435283.
- The Complete Najdorf 6. Bg5 (1997), International Chess Enterprises. ISBN 1-879479-45-1.
- Complete Najdorf: Modern Lines (1999), Sterling Pub Co Inc. ISBN 0-7134-8218-4.
- The Complete Pirc (1989), Batsford. ISBN 0-7134-5389-3.
- Endgame Challenge (2002), Gambit Publications. ISBN 1-901983-83-8.
- Grandmaster Chess Move by Move (2005), Gambit Publications. ISBN 1-904600-34-4.
- John Nunn's Best Games (2001), Batsford. ISBN 0-7134-7726-1.
- John Nunn's Chess Puzzle Book (1999), Gambit Publications. ISBN 1-901983-08-0.
- The King-Hunt (1996, with William Cozens), Batsford. ISBN 0-7134-7945-0.
- Learn Chess (2000), Gambit Publications. ISBN 1-901983-30-7.
- Learn Chess Tactics (2004), Gambit Publications. ISBN 1-901983-98-6.
- Mammoth Book of the World's Greatest Chess Games (2004, with Graham Burgess and John Emms), Carroll & Graf. ISBN 0-7867-1411-5.
- New Ideas in the Pirc Defence (1993), Batsford. ISBN 0-7134-7237-5.
- Nunn's Chess Openings (1999), with Joe Gallagher, John Emms, and Graham Burgess, Everyman Chess. ISBN 1-85744-221-0.
- Nunn's Chess Endings, volume 1 (2010), Gambit Publications. ISBN 978-1-906454-21-0.
- Nunn's Chess Endings, volume 2 (2010), Gambit Publications. ISBN 978-1-906454-23-4.
- Secrets of Grandmaster Chess (1997), International Chess Enterprises. ISBN 1-879479-54-0.
- Secrets of Practical Chess (1998), Gambit Publications. ISBN 1-901983-01-3. Second edition 2007, ISBN 978-1-904600-70-1.
- Secrets of Minor-Piece Endings (2001), Rowman Littlefield. ISBN 0-7134-7727-X.
- Secrets of Pawnless Endings (1994, 2002), Gambit Publications. ISBN 1-901983-65-X.
- Secrets of Rook Endings (1992, 1999), Gambit Publications. ISBN 1-901983-18-8.
- Solving in Style (1985 Batsford) then (2002), Gambit Publications. ISBN 1-901983-66-8.
- Tactical Chess Endings (2003), Batsford. ISBN 0-7134-5937-9.
- Understanding Chess Endgames (2009), Gambit Publications. ISBN 978-1-906454-11-1
- Understanding Chess Move by Move (2001), Gambit Publications. ISBN 1-901983-41-2.
- Understanding Chess Middlegames (2011), Gambit Publications. ISBN 1-906454-27-2.