How old was Bobby Fischer when he became a chess grandmaster?

Robert James "Bobby" Fischer (March 9, 1943 – January 17, 2008) was an American chess grandmaster and the eleventh World Chess Champion. He is considered by many to be the greatest chess player who ever lived.

Fischer was a chess prodigy and at age 13 he won a "brilliancy" that became known as The Game of the Century. Starting at age 14 he played in eight United States Championships, winning each by at least a point. At age 15½, he became both the youngest grandmaster and the youngest candidate for the World Championship up to that time. He won the 1963–64 U.S. Championship with 11/11, the only perfect score in the history of the tournament. His book My 60 Memorable Games published in 1969, remains a revered part of chess literature for advanced players.

In the early 1970s he became one of the most dominant players in history. Bobby became the first official World Chess Federation (FIDE) number-one ranked chess player in July 1971, and spent 54 total months at number one. In 1972, he captured the World Championship from Boris Spassky of the USSR in a match widely publicized as a Cold War confrontation. The match was held in Reykjavík, Iceland and attracted more worldwide interest than any chess match before or since.