Championships
In 2001, Lékó became the first Fischer Random Chess world champion, defeating GM Michael Adams in an eight-game match played as part of the Mainz Chess Classic. There were no qualifying matches (also true of the first orthodox world chess champion titleholders), but both players were in the top five in the January 2001 world rankings for orthodox chess. Lékó was chosen because of the many novelties he has introduced to known chess theories, as well as his previous tournament win; in addition, Lékó has supposedly played Fischer Random Chess games with Fischer himself. Adams was chosen because he was the world number one in blitz (rapid) chess and is regarded as an extremely strong player in unfamiliar positions. The match was won by a narrow margin, 4½ to 3½.
In 2002 at Mainz, an open tournament was held which attracted 131 players. Peter Svidler won the event. Other interesting events happened in 2002. The website ChessVariants.org selected Fischer Random chess as its "Recognized Variant of the Month" for April 2002. Yugoslavian Grandmaster Svetozar Gligorić published in 2002 the book Shall We Play Fischerandom Chess?, popularizing this variant further.
At the 2003 Mainz Chess Classic, Svidler beat Lékó in an eight game match for the World Championship title by a score of 4½-3½. The Chess960 open tournament attracted 179 players, including 50 GMs. It was won by Levon Aronian, the 2002 World Junior Champion. Svidler is the official first World New Chess Association (WNCA) world champion inaugurated on August 14, 2003 with Jens Beutel, Mayor of Mainz as the President and Hans-Walter Schmitt, Chess Classic organiser as Secretary. The WNCA maintains an own dedicated Chess960 rating list.
Aronian played Svidler for the title at the 2004 Mainz Chess Classic, losing 4½–3½. At the same tournament in 2004, Aronian played two Chess960 games against the Dutch computer chess program The Baron, developed by Richard Pijl. Both games ended in a draw. It was the first ever man against machine match in Chess960. Zoltán Almási won the Chess960 open tournament in 2004.
Almási and Svidler played an eight-game match at the 2005 Mainz Chess Classic. Once again, Svidler defended his title, winning 5–3. Levon Aronian won the Chess960 open tournament in 2005. During the Chess Classic 2005 in Mainz, initiated by Mark Vogelgesang and Eric van Reem, the first-ever Chess960 computer chess world championship was played. Nineteen programs, including the powerful Shredder, played in this tournament. As a result of this tournament, Spike became the first Chess960 computer world champion.
The 2006 Mainz Chess Classic saw Svidler defending his championship in a rematch against Levon Aronian. This time, Aronian won the match 5–3 to become the third ever Fischer Random Chess World Champion. Étienne Bacrot won the Chess960 open tournament, earning him a title match against Aronian in 2007. In 2006 Shredder won the computer championship, making it Chess960 computer world champion. Three new Chess960 world championship matches were held, in the women, junior and senior categories. In the women category, Alexandra Kosteniuk became the first Chess960 Women World Champion by beating Elisabeth Paehtz 5½ to 2½. The 2006 Senior Chess960 World Champion was Vlastimil Hort, and the 2006 Junior Chess960 World Champion was Pentala Harikrishna.
In 2007 Mainz Chess Classic Aronian successfully defended his title of Chess960 World Champion over Viswanathan Anand, while Victor Bologan won the Chess960 open tournament. Rybka won the 2007 computer championship.
The last Mainz tournament was held in 2009.