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
FIDE World Chess Championship 2005 be required to compete; but that as part of the "Prague Agreement", his defense of his title in the Classical World Chess Championship 2004 entitled him to direct entry to a match against the FIDE World Champion for the unified world title. After the tournament, he expressed his willingness to play such a match against Topalov. Although Topalov initially declined Kramnik's offer, he later acceded. The two contested the FIDE World Chess Championship 2006 to reunify the title, with Kramnik emerging the winner. FIDE World Chess Championship 2005 The FIDE World Chess Championship 2005 took place in Potrero de los