World Chess Championship a Kasparov match, either with 2002 FIDE champion Ponomariov, or 2004 FIDE champion Kasimdzhanov. Partly due to his frustration at the situation, Kasparov retired from chess in 2005, still ranked No. 1 in the world. Soon after, FIDE dropped the short knockout format for a World Championship and announced the FIDE World Chess Championship 2005, a double round robin tournament to be held in San Luis, Argentina between eight of the leading players in the world. However Kramnik insisted that his title be decided in a match, and declined to participate. The tournament was convincingly won by the Bulgarian Veselin
Development of the World Chess Championship not claim the title himself. Subsequent world championship matches returned to the format of a match between the champion and a challenger. The World Chess Championship 2008 was a 12-game match between the current champion Viswanathan Anand and 2006 champion Vladimir Kramnik. Anand convincingly defended his title in 11 games with 6½–4½. The World Chess Championship 2010 took place in April and May 2010, where Anand defeated 2005 FIDE champion Veselin Topalov (who defeated Chess World Cup 2007 winner Gata Kamsky in a match in February 2009 to determine Anand's challenger) to defend the title for the second time. FIDE