Tigran Petrosian (1929-1984) was World Chess Champion from 1963 to 1969 and was one of the strongest players in the world throughout his lengthy career. Petrosian was a Candidate for the World Championship on eight occasions (1953, 1956, 1959, 1962, 1971, 1974, 1977 and 1980). He won the world championship in 1963 by defeating Botvinnik, successfully defended it in 1966 against Spassky, and lost it in 1969 to Spassky. Thus, he was the defending World Champion or a World Champion Candidate in ten consecutive three-year cycles. This book was originally published in Descriptive Chess Notation. Since that time, Descriptive has become almost obsolete. For that reason, all 50 games in this book have been converted into modern Algebraic Notation and are included in an appendix in the back of the book.