Post-war era (1945 and later)

After the death of Alekhine, a new World Champion was sought in a tournament of elite players ruled by FIDE, who have controlled the title since then, with one interruption. The winner of the 1948 tournament, Russian Mikhail Botvinnik, started an era of Soviet dominance in the chess world. Until the end of the Soviet Union, there was only one non-Soviet champion, American Bobby Fischer (champion 19721975).[64] In the previous informal system, the World Champion decided which challenger he would play for the title and the challenger was forced to seek sponsors for the match.[65] FIDE set up a new system of qualifying tournaments and matches. The world's strongest players were seeded into "Interzonal tournaments", where they were joined by players who had qualified from "Zonal tournaments". The leading finishers in these Interzonals would go on the "Candidates" stage, which was initially a tournament, later a series of knock-out matches. The winner of the Candidates would then play the reigning champion for the title. A champion defeated in a match had a right to play a rematch a year later. This system worked on a three-year cycle.[65] Botvinnik participated in championship matches over a period of fifteen years. He won the world championship tournament in 1948 and retained the title in tied matches in 1951 and 1954. In 1957, he lost to Vasily Smyslov, but regained the title in a rematch in 1958. In 1960, he lost the title to the Latvian prodigy Mikhail Tal, an accomplished tactician and attacking player. Botvinnik again regained the title in a rematch in 1961. Following the 1961 event, FIDE abolished the automatic right of a deposed champion to a rematch, and the next champion, Armenian Tigran Petrosian, a genius of defense and strong positional player, was able to hold the title for two cycles, 19631969. His successor, Boris Spassky from Russia (19691972), was a player able to win in both positional and sharp tactical style.[66] Current World Champion Viswanathan Anand The next championship, the so-called Match of the Century, saw the firs non-Soviet challenger since World War II, American Bobby Fischer, who defeated his Candidates opponents by unheard-of margins and clearly won the world championship match. In 1975, however, Fischer refused to defend his title against Soviet Anatoly Karpov when FIDE refused to meet his demands, and Karpov obtained the title by default. Karpov defended his title twice against Viktor Korchnoi and dominated the 1970s and early 1980s with a string of tournament successes.[67] Karpov's reign finally ended in 1985 at the hands of another Russian player, Garry Kasparov. Kasparov and Karpov contested five world title matches between 1984 and 1990; Karpov never won his title back.[68] In 1993, Garry Kasparov and Nigel Short broke with FIDE to organize their own match for the title and formed a competing Professional Chess Association (PCA). From then until 2006, there were two simultaneous World Champions and World Championships: the PCA or Classical champion extending the Steinitzian tradition in which the current champion plays a challenger in a series of many games; the other following FIDE's new format of many players competing in a tournament to determine the champion. Kasparov lost his Classical title in 2000 to Vladimir Kramnik of Russia. Earlier in 1999, Kasparov as the reigning world champion played a game online against the world team composed of more than 50,000 participants from more than 75 countries. The moves of the world team were decided by plurality vote, and after 62 moves played over four months Kasparov won the game. The number of ideas, the complexity, and the contribution it has made to chess theory make it one of the most important chess games ever played.[69] The FIDE World Chess Championship 2006 reunified the titles, when Kramnik beat the FIDE World Champion Veselin Topalov and became the undisputed World Chess Champion.[70] In September 2007, Viswanathan Anand from India became the next champion by winning a championship tournament.[71] In October 2008, Anand retained his title, decisively winning the rematch against Kramnik.