In 1976, Miles became the first UK-born, chess
grandmaster, narrowly beating
Raymond Keene to the accolade. this record was not broken until 2009. On the January 1984
Elo rating list, he ranked No. 18 in the world with a rating of 2599. One of his best results occurred at the
Tilburg tournament in 1984, where, from a strong field, he emerged sole winner by a clear margin of one and one-half points. The following year, he tied for first at the same event with
Robert Hübner and
Viktor Korchnoi, playing several of his games while lying face down on a table, having injured his back. The result was controversial, as many of Miles's opponents felt they were distracted by the unusual circumstances. A string of good performances culminated in a good showing on the January 1986 Elo rating list, where he climbed to a best-ever position of World No. 9 with a rating of 2610. During this period, there was considerable rivalry with
John Nunn over who was the United Kingdom's best player, the two protagonists regularly leapfrogging each other in the world rankings.
Nigel Short and
Jon Speelman soon added to the competition, as the English national squad entered its strongest period. Never able to qualify out of the
Interzonal stages into the
Candidates' series, Miles eventually lost the race to become the first British Candidate when Short did so in 1985. However, he retained top board for England at the
Thessaloniki and
Dubai Olympiads of 1984 and 1986, helping the team to silver medals at each. Against
Garry Kasparov, Miles had little success, not winning a game against him, and losing a 1986 match in
Basel by the score of 5½–½. Following this encounter, Miles commented "I thought I was playing the world champion, not a monster with a thousand eyes who sees everything" (some sources alternatively quote Miles as having the opinion that Kasparov had 22 or 27 eyes). (1985) After he was hospitalised because of a mental breakdown in late 1987, Miles moved to the
United States. He finished last in the 1988 U.S. Championship, but continued to play there and had some good results, such as a victory in the 1990
U.S. Masters Chess Championship. In 1991, he played in the Championship of Australia, but eventually moved back to England and began to represent his native country again. He was equal first at the very strong
Cappelle-la-Grande Open in 1994, 1995, and 1997, and caused a shock at the PCA Intel Rapid Chess Grand Prix in London in 1995, when he knocked out
Vladimir Kramnik in the first round and
Loek van Wely in the second. His bid to win the event was finally halted in the semifinal by English teammate
Michael Adams. There were four notable victories at the
Capablanca Memorial in
Cuba (1994, 1995, 1996, and 1999). Miles also tied for first in the 1999 Continental Open in
Los Angeles with
Alexander Beliavsky,
Ľubomír Ftáčnik and
Suat Atalık. His last tournament victory was the 2001
Canadian Open Chess Championship in
Sackville, New Brunswick. Miles entered and played at the 2001 British Championship in
Scarborough, but withdrew before the final round, apparently because of ill health. His final two games before his death were short
draws in the
Four Nations Chess League. Miles played in an extraordinary number of chess events during his career, including many arduous weekend tournaments. The
Miles Variation (1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.Bf4) in the
Queen's Indian Defence is
named after him. ==Death==