Viktor Korchnoi alleged that when acting as his second in the 1978 World Championship match, Keene broke his contract by writing a book about the match (which appeared three days after the match finished) having specifically signed an agreement "not to write, compile or help to write or compile any book during the course of the match". Korchnoi commented: "Mr Keene betrayed me. He violated the contract. It was clear that while Mr Keene was writing one book and then another, Mr Stean was doing his work for him."