The players

At the time of the match, Karpov had a FIDE rating of 2720, while Kasparov was close behind with a rating of 2700. There was a large difference in age between the two players, with Karpov (34) the older by 12 years.

Between the end of the 1984 match and the start of the 1985 match, Kasparov played matches against Robert Hübner in Germany, winning three games and drawing three, and against Ulf Andersson in Sweden, winning two games and drawing four.^[4]

Karpov also showed that he was still in good form when he won the 1985 OHRA tournament in Amsterdam with 7/10, not losing a game^[5] and winning four.^[6]

As in previous World Chess Championships, each of the contestants employed other chess players as "seconds" to help with preparation and analysis of adjourned games. Karpov's seconds were Grandmasters Sergey Makarichev and Igor Zaitsev. Other assistance was provided by Efim Geller and Evgeni Vasiukov. Kasparov's seconds were Grandmaster Josif Dorfman and Alexander Nikitin with Gennadi Timoshchenko and Evgeny Vladimirov also helping.

The match

The 1985 championships represented a restart of the abandoned match. Due to the extreme duration of the previous match, FIDE agreed at a meeting in Tunisia in July 1985 that the re-arranged championship would be of fixed length, played as the best of 24 games. If the match had ended at a 12–12 draw, Karpov would have retained his title.^[7] As Karpov had been leading the 1984 championships, he was also granted an automatic rematch if he lost.^[4]

The playing regulations were that 40 moves should be made by each player in 2 hours 30 minutes, with games being adjourned to the following day after 40 moves were completed.^[8]

Kasparov's preferred venue was Leningrad and bids for the match had been received from London and Marseille. In the end, with the backing of the Soviet Chess Federation, FIDE selected Moscow's Tchaikovsky Concert Hall as the venue for the match.^[4]

The opening ceremony was held on 2 September, at which the draw for colours was made and won by Kasparov. This meant that he took the white pieces in Game 1, which started on 3 September 1985.^[4]

Game 1 and 2 – Karpov "stunned"

In Kasparov's own words, his choice of opening for game 1 "stunned" Karpov,^[9] as the position after only 4 moves was one that had not appeared in any of their previous games. Indeed, the position after move 5 had never previously appeared in any game that Karpov had played, and Karpov's first five moves took him 50 minutes to play.^[9] Kasparov won the game in 42 moves.

Karpov took White in game 2, which was drawn in 65 moves. Kasparov's analysis suggests that he could have won the game.^[10]

Games 3 to 5 – Karpov turns the tables

Game 3 was again drawn, this time in only 20 moves with few chances for either side.^[11] Game 4 was won by Karpov as White in 63 moves. Kasparov noted that "the entire plan [after Black's 21st move] was put into practice by Karpov extremely strongly and consistently."^[12] In game 5, Kasparov played with the white pieces and made a number of mistakes and Karpov won in 41 moves. This meant that Karpov had moved from a one-point deficit to a one-point lead in just three days.^[13]

Kasparov resolved at this stage "to play as resolutely as possible" and "to go in for a complicated struggle in order to regain the match initiative and if possible wear out my opponent".^[13]

Games 6 to 15 – Kasparov equalises

Kasparov-Karpov, Game 11

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

Karpov played 22 ... Rcd8?? which was met by 23 Qxd7 Rxd7 24 Re8+ Kh7 25 Be4+ winning two rooks and a minor piece for a queen after 25 ... g6 Rxd7

After such a flurry of excitement, it is perhaps understandable that the players regrouped in the following game, which was a short 27-move draw.^[14] The following four games also ended in draws, with Karpov having slightly the worse of at least two games, but with Kasparov unable to force a victory.^[15]

Kasparov reports speaking to grandmaster Andras Adorjan after game 10, lamenting the opportunities he felt he had missed in games 7, 9 and 10. Adorjan stated 'The main thing is not the score, but the trend, which, in my opinion is favourable'.^[16] Adorjan's statement came true in game 11, which was won by Kasparov in just 25 moves, following an oversight by Karpov on move 22.^[17][18]

Games 12, 13 and 15 were all drawn quickly.^[19] Game 14 also ended in a draw after forceful and accurate play on both sides. Kasparov later rated game 14 as "perhaps the 'cleanest' game of the match".^[20]

So the scores after 15 games were level at 7½–7½, and the match was already past the halfway point.

Game 16 – Kasparov's masterpiece

The first 10 moves of game 16 were identical to those from game 12. Karpov was the first to deviate, but Kasparov had analysed the position deeply in his preparation before the match, and was able to take the initiative, despite playing with the black pieces.

Kasparov's positioning of a knight deep in his opponent's position as early as move 16 (see first diagram) was spectacular and ultimately decisive. The knight remained in place until move 34, when Karpov was forced to sacrifice his queen to remove it.

Chess Informant readers selected this game as the best game of the first 64 issues.^[4]

The game progressed as follows (notes based on Kasparov's analysis):

Karpov–Kasparov, Game 16

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

(after 16 ... Nd3)

1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nc6 5.Nb5 d6 6.c4 Nf6 7.N1c3 a6 8.Na3 d5 9.cxd5 exd5 10.exd5 Nb4 11.Be2 Bc5

This move is no longer played at the top level as it was found shortly after the game that White can play 12.Be3 Bxe3 13 Qa4+ retaining the extra pawn without the difficulties encountered in this game.^[21]

12.O-O O-O 13.Bf3 Bf5

After 13 Bg5 Nbxd5 14 Nxd5 Qxd5 15 Bxf6 Qxd1 16 Rfxd1 gxf6, Black should draw easily. Kasparov commented that he thought that Karpov felt obliged to play for the win in this position.^[22]

14.Bg5 Re8 15.Qd2 b5 16.Rad1 Nd3

(see diagram) The "octopus knight" begins to dominate White's position.

17.Nab1

Karpov could have played more actively here. 17. d6 would have been better, although Black's position is still superior after 17. ... Qxd6 18. Bxa8 Rxa8.^[23]

17. ... h6 18.Bh4 b4 19.Na4 Bd6

Kasparov said that he had reached this position in his home preparation: "A position for which I had aimed in my preparatory analysis! Black has achieved obvious advantage. White scattered his minor pieces about on either flank and are quite unable to coordinate, the placement of the knights being particularly depressing. But Black has the wonderful duo of Bf5 and Nd3 which completely paralyzes all three White major pieces—a very rare occurrence in a practical game!"^[24]

Karpov–Kasparov, Game 16

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

(final position after 40 ... Re1+)

20.Bg3 Rc8 21.b3 g5 22.Bxd6 Qxd6 23.g3 Nd7 24.Bg2 Qf6 25.a3 a5 26.axb4 axb4 27.Qa2 Bg6 28.d6 g4 29.Qd2 Kg7 30.f3

Kasparov has slowly been building up the pressure on Karpov's position, and Karpov finally decides to try to break out.^[25]

30. ... Qxd6 31.fxg4 Qd4+ 32.Kh1 Nf6 33.Rf4 Ne4 34.Qxd3

The knight is finally taken from d3, but it costs Karpov his queen.

34. ... Nf2+ 35.Rxf2 Bxd3 36.Rfd2 Qe3 37.Rxd3

Karpov now has three pieces for the queen (normally a reasonable exchange) but his pieces are not sufficiently co-ordinated to counter Kasparov's attack.^[26]

37. ... Rc1 38.Nb2 Qf2 39.Nd2 Rxd1+ 40.Nxd1 Re1+ White resigns 0-1 (see second diagram)

Games 17 to 23 – Honours even

Games 17 and 18 were short draws.^[27] In game 19, Karpov, with the black pieces, adopted an unusual opening strategy^[28] which eventually backfired on him. Kasparov won the game in 42 moves, to extend his lead to 2 points. With Kasparov now needing only four draws from five games to become World Champion, Karpov needed to start winning games.

In game 20, Karpov fought hard to force a victory, but was unable to win the game, and a draw was agreed after 85 moves.^[29] Game 21 also ended in a draw, this time with Kasparov generally in the ascendancy for the majority of the game.^[30]

In game 22, Kasparov made a serious mistake from a good position, and lost the game after further mistakes from both sides.^[31]

Game 23 ended in a draw, leaving Kasparov on 12 points against Karpov's 11.^[32] Karpov needed to win with the white pieces to retain the title.

Game 24 – Karpov's must-win game

Everything was to be decided in the final game, where Karpov needed a win to even the match and retain the title. This was reminiscent of the 30th game of the Euwe vs Alexander Alekhine 1935's match, in that the latter was too in a 'must win' situation.

Kasparov called game 24 the "game of his life" and has stated that working out the strategy for this encounter was difficult for him. His playing style did not lend itself to playing for a draw, so he decided to accept an open battle, with chances on both sides.^[33]

Karpov began a direct attack on Kasparov's king as early as move 15, and had chances to build up a strong attack. Kasparov sacrificed a pawn to blunt the attack and then a second pawn to launch a blistering counterattack. Under pressure from the clock, Karpov made decisive errors on move 36^[34] and move 40. Kasparov won the World Championship after Karpov resigned on move 42.