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 2008, which Anand won. Then Topalov was seeded directly into the Candidates final of the World Chess Championship 2010. He won the Candidates (against Gata Kamsky). Anand again won the championship match. The next championship, the World Chess Championship 2012, had short knock-out matches for the Candidates Tournament. This format was not popular with everyone, and world #1 Magnus Carlsen withdrew in protest. Boris Gelfand won the Candidates. Anand won the championship match again, in tie breaking rapid games, for his fourth consecutive world championship win. Since 2013, the Candidates have been an 8 player double round robin tournament, with