World Chess Championship Topalov, and negotiations began for a Kramnik–Topalov match to unify the title. The FIDE World Chess Championship 2006 reunification match between Topalov and Kramnik was held in late 2006. After much controversy, it was won by Kramnik. Kramnik thus became the first unified and undisputed World Chess Champion since Kasparov split from FIDE to form the PCA in 1993. Kramnik played to defend his title at the World Chess Championship 2007 in Mexico. This was an 8-player double round robin tournament, the same format as was used for the FIDE World Chess Championship 2005. This tournament was won by Viswanathan
World Chess Championship 1963 title in 1966, before losing the title to Boris Spassky in 1969. World Chess Championship 1963 At the World Chess Championship 1963 Tigran Petrosian narrowly qualified to challenge Mikhail Botvinnik for the World Chess Championship, and then won the match to become the ninth World Chess Champion. The cycle is particularly remembered for the controversy surrounding the Candidates' Tournament at Curaçao in 1962, which resulted in FIDE changing the format of the Candidates Tournament to a series of knockout matches. The world championship cycle was under the jurisdiction of FIDE, the World Chess Federation, which set the structure for the