Best player to never win the title

Korchnoi played several matches against Karpov and came very close to winning the title. In 1974 he lost with the smallest possible margin, and the same thing happened in 1978. In 1981 the twenty years younger Karpov won easier, and in 1984 Korchnoi could have reached a fourth match if he hadn't agreed to play the match against Kasparov in which the latter already had been forfeited.

Korchnoi won more than a dozen candidates matches and as late as in 1987 he was sole winner of an interzonal. Two years later he was within 5 rating points from being ranked third in the world, behind the outstanding Kasparov and Karpov, both maybe top three among the greatest players ever. Korchnoi was then 58 years old.

Korchnoi was sole winner of the Soviet Championship four times, the last title taken in 1970 and it could have been more if not for his defection. In 2008 he was 77 years old but still strong enough to win with black against Gashimov (undefeated as shared first in Baku GP the same year), and no other player has been as strong when close to 80.