Continuing with Two World Champions in Combat, the following remarks by Kasparov must have impressed GM Taimanov as much as they impressed me. He quoted the entire second paragraph ['World Chess Championship, Karpov - Kasparov, Moscow 1985' by Averbakh & Taimanov; p.136].
Q: What was the basis of your preparation for this second match?
A: This time the preparation was both more complicated and more straightforward. More complicated because there was so little time. I had to renew my reserves of nervous energy. We all understood that the nervous tension would be much greater. We were all convinced that the fight would be of a totally different nature and we would need to be prepared for the widest variety of possible situations.
As for the purely theoretical work, we managed to work through a whole mass of information and we evaluated it correctly. We took a great deal into consideration. Our choice of new openings was based on all this work. Let us take, for example, the Nimzo-Indian Defense, which was so successful for us. It is incidentally, one of the cornerstones of Karpov's openings which we had not tested until now in our games. And using this opening he got, as we say, "minus three" he lost three games [with no wins]. That is the advantage of preparatory theoretical study! And I am convinced that it is possible to impose one's own play on a game only if one has had the best possible preparation and can create a sufficient number of surprises for one's opponent.
Q: What do you think of Karpov's play in this match?
A: [...] The decisive factor was how each player approached the second match, who had the richer store of ideas, and who had evaluated the first match the better.
In my opinion, Karpov made a serious mistake in not drawing his conclusions from the final games of the first match, and in not properly assessing the facts at his disposal. We managed to understand Karpov's game, which is easier said than done, but it took us until the tenth game of the new match before we were sure that we had made the right preparation. We got the impression that Karpov had exaggerated his abilities when playing on "my" territory, and had underestimated the strong sides of my game.
I'm not completely certain what Kasparov meant in the first paragraph when he wrote about being 'prepared for the widest variety of possible situations'. At first reading I thought he meant different scenarios where he would be leading or behind after 'X' number of games with 'Y' number still to be played. Then it occurred to me that he might be talking about situations (i.e. positions) appearing on the board.
Kasparov wrote his own book on the second K-K match, where he had further comments on the subject of World Championship Opening Preparation. I'll discuss those another time.