In 1973, Miles won the silver medal at the World Junior Chess Championship at Teesside, his first important event against international competition.

Both he and compatriot Michael Stean defeated the tournament winner Alexander Beliavsky, but were unable to match the Soviet player's ruthlessness in dispatching lesser opponents.

[1][2] Taking the decision to pursue the game professionally, Miles did not complete his studies; however, in 1975, he was awarded an MA by the university in respect of his chess achievements.

He matured into a world-class player and won games against high-calibre opponents such as former World Chess Champions Vasily Smyslov, Mikhail Tal and Boris Spassky.

In 1980, at the European Team Championship in Skara, he beat reigning World Champion Anatoly Karpov with Black, using the extremely unorthodox opening 1. e4 a6!

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.

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.

Miles made accusations regarding payments that Keene had received from the British Chess Federation for acting as his assistant in the 1985 Interzonal tournament in Tunis.

He was arrested in September 1987 in Downing Street, apparently under the belief that he had to speak to then-Prime Minister Margaret Thatcher about the matter; he was subsequently hospitalised for two months.

[10] Writing in The Daily Telegraph in November 2003, Short said that "Tony was insanely jealous of my success, and his inability to accept that he was no longer the UK's number one was an indication of, if not a trigger for, his descent into madness.

"[11] Miles was also noted for his acerbic wit; according to Genna Sosonko, he was "a master of the laconic barb, the sarcastic remark, and he was never at a loss for words".

"[13] His review of Eric Schiller's book Unorthodox Chess Openings (Cardoza Publishing, 1998) which appeared in Kingpin consisted of just two words: "Utter crap.