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
World Senior Chess Championship the men's section. So far one male World Chess Champion – Vasily Smyslov – has gone on to win the World Senior Championship as well (at age of 70 in 1991). He has also been the first Senior World Chess Champion ever. Nona Gaprindashvili is the only female World Chess Champion to obtain the World Senior title as well. The oldest World Senior Champion, male or female - before the split in two different age categories has been made - is Viktor Korchnoi who won the title at age of 75 and a half (in 2006, his only participation). Vlastimil