Candidates Tournament

During its 1993 to 2006 split from FIDE, the "Classical" World Championship also held three Candidates Tournaments (in 1994–1995, 1998 and 2002) under a different sponsor and a different format each time.

In one of these cases (Alexei Shirov in 1998) no title match eventuated, under disputed circumstances (see Classical World Chess Championship 2000).

Normally, the incumbent champion is seeded directly into the final against the challenger (who had to pass through the Candidates qualification), but there have been exceptions: The incumbent champion Bobby Fischer refused to defend his title at the World Chess Championship 1975, and his challenger Anatoly Karpov won by forfeit.

Magnus Carlsen refused to defend his title at the World Chess Championship 2023 and was replaced by the runner-up of the Candidates Tournament, Ding Liren.

The Swiss-system FIDE Grand Swiss was introduced in the latter half of 2019, acting as another qualification path for the 2020 Candidates Tournament.