Miles had a string of good results in the late 1970s and 1980s, and his success was a factor in the growth of strong British players shortly after Miles became a GM. Miles won games against a number of former World Chess Champions, including 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!?, the so-called English Defence. Miles beat Karpov again three years later in Bath in a game that was part of the BBC's "Mastergame" series, but it was never shown on television due to a technicians' strike. However, over their careers, Karpov won most of the other encounters.