Development of the World Chess Championship five incredibly close world championship matches, the World Chess Championship 1984 (controversially terminated without result with Karpov leading +5 -3 =40), World Chess Championship 1985 (in which Kasparov won the title, 13–11), World Chess Championship 1986 (narrowly won by Kasparov, 12½–11½), World Chess Championship 1987 (drawn 12–12, Kasparov retaining the title), and World Chess Championship 1990 (again narrowly won by Kasparov, 12½–11½). In 1993, Kasparov and challenger Nigel Short complained of corruption and a lack of professionalism within FIDE and split from FIDE to set up the Professional Chess Association (PCA), under whose auspices they held their match. FIDE and
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