When he sat down to play Kasparov in the first game a month ago, he felt well prepared, both technically and psychologically, to face the man who has been the world's strongest player for a decade.
The first eight games - all drawn - must have encouraged his belief that the match could be won. Kasparov had produced few original ideas and had seemed to be lacking in fighting spirit. In a generally lacklustre fortnight, the only lost chance had been when Anand missed a winning combination in the third game.
Then in game nine, the Indian went ahead with a powerful positional game - and suddenly Kasparov snapped out of his torpor. In the next five games, Anand could only scrape a single half-point.
What went wrong? Well his loss in game 10, falling into a brilliant piece of opening preparation, could be written off as an occupational hazard of playing the same high-risk Open Variation of the Ruy Lopez that had served him well in an earlier game. But his two losses with White, in games 11 and 13, exposed a deep failing in Anand's preparations.
When Kasparov switched from his favourite Najdorf Sicilian to the Dragon Variation, Anand had a difficult choice to make. After the characteristic Dragon moves, 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 g6, White has three basic options:
1) The most aggressive line - indeed the line that has effectively put the Dragon out of business in top-level play for the past quarter of a century - is the Yugoslav Attack: 6.Be3 Bg7 7.f3 0-0 8.Qd2 Nc6 9.Bc4, followed by 0-0-0, h4, g4, Bh6 and the sort of attack you can play on automatic pilot.
2) ... but the Yugoslav Attack has been extensively analysed, and the fashionable variation with 9...Bd7 10.0-0-0 Rc8 11.Bb3 Ne5 12.h4 h5 13.Bg5 has not been doing badly for Black recently, so perhaps an early divergence with 9.0-0-0 or 9.g4 would be in order.
3) ... or it might be better to cop out with one of the quieter positional variations introduced by 6.Be2 or 6.g3.
Anand, with the memory of game 10 still fresh in his mind, could not have relished the prospect of galloping headlong into another piece of Kasparov analysis. Yet by choosing to play the Yugoslav Attack, then opting out of its main line by playing the cautious 13.Kb1 instead of Bg5, he conceded easy equality to Black.
Two games later, he tried the wretched plan of 10.h4 h5 11.Nxc6?, of which the only value was that of surprise. But any bad move has surprise value. Anand's failure was in having no contingency plans for coping with the unexpected. Kasparov's Dragon knocked him off balance. Anand simply did not understand what was this "world championship match".