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
Hermann Helms their well-respected 1995 book "The Bobby Fischer I Knew And Other Stories" (p. 329), which is the major source for this article. Helms assisted Bobby Fischer in 1951 with his move into organized chess, when he responded to a letter from Bobby's mother Regina Fischer, who was seeking opponents in Brooklyn for her eight-year-old son. Helms encouraged and stimulated the young Fischer, who would develop very rapidly, and become U.S. Champion by age 14 in 1957, later going on to win the World Chess Championship in 1972. There is a small file of ten of his games at chessgames.com. This