Several years ago, when I was working on a page for the 1992 Fischer - Spassky Rematch : Highlights, I noted the following:
A Memorable Press Conference: On 1 September 1992, Fischer gave his first press conference in 20 years. [...] He accused Kasparov and Karpov of playing "prearranged" matches, and accused Karpov and Korchnoi of the same. Spassky supported the opinion by pointing out the finish of the 19th game of the 1990 match in Lyon.
The full quote by Fischer from the press conference, repeated by GM Larry Evans in Chess Life, was, 'These criminals Karpov and Kasparov have been ruining chess with immoral, unethical, prearranged games, and are the lowest dogs around.' (CL, November 1992, p.56)
At the time the match was played, and for years afterward, I completely misunderstood what Fischer was saying. I thought he suspected that the two Ks had somehow colluded before their games, agreeing on which moves would be played and what the result of the game would be. The reason for their doing this, as I understood Fischer's thinking, was to scrap the scoring system of a fixed number of wins and an unlimited number of games to determine the World Champion.
Fischer had fought to introduce this system after becoming World Champion in 1972 and had prevailed. All of the candidate matches in the cycle leading to the 1975 match were playing using Fischer's scoring system. The system was abandoned after the first K-K match (see 1984 Karpov - Kasparov Title Match), which went to 48 games before being cancelled.
It wasn't until recently that I realized that when Fischer said 'prearranged', he was referring to the practice of preparing opening variations before the match, then playing moves during the game that had been discovered during the pre-game preparation. While Fischer had himself prepared this way in his heyday, the method of preparation had subsequently gotten out of hand with teams of seconds and computers working on the problem of anticipating and upsetting the future opponent's opening repertoire.
Little mention was made at the time of the 1992 match, but Fischer also said during his press conferences that he was working on a method of play where a game started with the pieces shuffled on the back rank. According to Wikipedia's page on Chess960, Fischer formally announced his new way of playing on 19 June 1996, in Buenos Aires, Argentina, almost four years after the start of the 1992 match. This would eliminate the problem of 'prearranged' games.
Stories relating to important games decided by pre-game opening preparation crop up frequently. I'll cover some of them in future posts.