Chess right of a deposed champion to a rematch, and the next champion, Armenian Tigran Petrosian, a player renowned for his defensive and positional skills, held the title for two cycles, 1963–1969. His successor, Boris Spassky from Russia (champion 1969–1972), won games in both positional and sharp tactical style. The next championship, the so-called Match of the Century, saw the first non-Soviet challenger since World War II, American Bobby Fischer, who defeated his Candidates opponents by unheard-of margins and clearly won the world championship match. In 1975, however, Fischer refused to defend his title against Soviet Anatoly Karpov when FIDE did
Bobby Fischer at his home in 1952. In the summer of 1955, Fischer, then 12 years old, joined the Manhattan Chess Club, the strongest chess club in the country. Fischer's relationship with Nigro lasted until 1956, when Nigro moved away. In June 1956, Fischer began attending the Hawthorne Chess Club, based in master John "Jack" W. Collins' home. For years it was believed that Collins was Fischer's teacher and coach, even though Collins stated that he did not teach Fischer. It is now believed that Collins was Fischer's mentor, not his teacher or coach. Fischer played thousands of blitz and offhand games