The World Chess Championship 1963, held in Moscow from March 23 to May 20, saw Tigran Vartanovich Petrosian defeat reigning champion Mikhail Botvinnik with a score of 12½–9½. Known as «Iron Tigran» for his exceptional defensive skills, Petrosian outmaneuvered Botvinnik in positional battles and demonstrated superior strategic depth. This marked the end of Botvinnik’s historic era as there was no provision for a rematch under the revised championship rules. Petrosian’s calm and impenetrable style set a new standard for positional chess, and his meticulous preparation was evident in his handling of critical moments throughout the match. His victory made him the 9th World Chess Champion, ushering in a new era of precise and resilient play at the top level.