In 1978, the World Chess Championship between the Soviet champion and convinced communist, Anatoly Karpov, and the dissident and defector, Viktor Korchnoi, turned into one of the most infamous clashes in the history of the game. At a time of peak Cold War tension, the two players traded allegations about yoghurts containing messages, the use of psychics and the mysterious appearance of a meditating yoga cult dressed in orange robes. David Edmonds tells the story of the match through the memories of British grandmaster, Michael Stean,

PHOTO: Anatoly Karpov and Viktor Korchnoi squaring up in 1978 (Getty Images)