Development of the World Chess Championship 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 Anand. Because Anand's World Chess Champion title was won in a tournament rather than a match, a minority of commentators questioned the validity of his title. Kramnik also made ambiguous comments about the value of Anand's title, but did
World Chess Championship 2010 tournament eventually won by Indian GM Viswanathan Anand to become the World Champion. Anand subsequently defended his title in a one-off match against Kramnik, the World Chess Championship 2008. The World Chess Championship format then returned to its original form, wherein a match between the current champion and a challenger would decide the World Champion. To choose the challenger, FIDE organized the Chess World Cup 2007. Topalov was compensated for missing the 2007 tournament by getting direct entry to a Challenger Match against the winner of the Chess World Cup. The winner of the Challenger Match would then be the