IN game four of their Candidates semi-final, Kasparov let Korchnoi play the Catalan, and the game was drawn.
Two games later, with the score 1-0 to Korchnoi (plus four draws), Kasparov returned to the Tarrasch.
Korchnoi (2600) - Kasparov (2690)
Candidates Semi-Final Game 6 (London) 1983
1.d4 d5 2.c4 e6 3.Nf3 c5 4.cxd5 exd5
One point of 3.Nf3 is that in the line 1.d4 d5 2.c4 e6 3.Nc3 c5 4.cxd5 Black can play the Von Hennig-Schara Gambit: 4...cxd4!? But the similar-looking line 1.d4 d5 2.c4 e6 3.Nf3 c5 4.cxd5 cxd4?! is crucially different because, with the knight on f3, White can play 5.dxe6, meeting 5...Bxe6 with 6.Qxd4 or, even better, according to Stockfish12 and Komodo11.01, 6.Nxd4!?
5.g3 Nc6
The first (minor) deviation from game two of the match, which saw 5...Nf6.
6.Bg2 Nf6 7.0-0 Be7 8.Be3!?
Mark Taimanov pioneered this. The idea is to force Black into an early decision about the c pawn.
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| How should Black proceed? |
*****
*****
*****
*****
*****
8...c4!?
This gives a position reminiscent of the start of the Swedish Variation.
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| The Swedish Variation begins 1.d4 d5 2.c4 e6 3.Nc3 c5 4.cxd5 exd5 5.Nf3 Nc6 6.g3 c4!? |
In the game position after 8...c4!?, Black has developed the kingside in a completely different way, but 8.Be3!? inhibits White from getting in e4. However, that is not White's only plan, as we shall see.
Second in popularity to 8...c4!? is 8...cxd4, when 9.Nxd4 0-0 10.Nc3 Re8 is reminiscent of the absolute main line except Black has not got in the move ...h6, which in the main line drives the white dark-square bishop from g5. Another possibility is 8...Ng4 but 9.Bf4 0-0 10.Nc3 is good for White, according to the engines.
9.Ne5 0-0 10.b3 cxb3 11.Qxb3
Black gets an IQP, as so often in the Tarrasch, but with the major difference that it is not on a half-open file and so is a lot less vulnerable.
11...Qb6?!
This seems questionable.
Taimanov - Lev Aronin, USSR Championship Semi-Final (Almaty) 1963, went 11...Na5 12.Qa4 a6 13.Bd2 Nc4!? 14.Nxc4 b5! 15.Qc2 bxc4 with approximately equal chances (½–½, 42 moves).
12.Rc1!?
12.Qxb6!? axb6 13.Nc3 Be6 was slightly better for White, according to the engines, in Paul van der Sterren (2515) - Jeroen Piket (2495), Netherlands Championship (Hilversum) 1990 (½–½, 57 moves).
12...Qxb3 13.axb3 Nb4 14.Na3 a6 15.Bd2
The knight on a3 has no real future, except to be exchanged for the advanced black knight, which prompts the thought 15.Nc2!?
15...Rb8 16.Bxb4 Bxb4 17.Nd3 Bd6 18.Nc2 Bg4 19.Kf1 Bf5 20.Nc5 Rfc8 21.Ne3 Be6 22.b4
22.Nxe6 fxe6 gets rid of Black's bishop-pair but exchanges a well-placed knight for a passive bishop and solves Black's difficulties with the IQP.
22...Kf8 23.Rc2 Ke7 24.Ke1 h5 25.Rb2!?
A passive square for the rook, but the idea is to redeploy the c5 knight without it then becoming tied to defending b4.
25...Rc7 26.Nd3 Ra8!
The idea is to meet 27.b5 with 27...a5. If Black had whiffed with, say 26...g6, then 27.b5 is strong as 27...axb5 runs into 28.Rxb5 Bd7 29.Rxd5! The engines point out Black can muddy the waters with 29...b6! (29...Nxd5?! 30.Nxd5+ Kd8 31.Nxc7), but the rook on d5 is hard to get at, eg 30.f4 Bc6 31.Re5+! Bxe5 32.fxe5 Ng4 33.Nxg4 Bxg2 34.Nf6 gives a position in which White only has a doubled pawn for the exchange but is much better, according to Stockfish12, although Komodo11.01 reckons Black is almost equal.
27.b5!?
Korchnoi sticks with his plan but after ...
27...a5 28.b6 Rc6
... the game is even, according to the engines.
29.Rb5 a4 30.Nxd5?!
Korchnoi correctly calculates that this wins a pawn, but Black gets connected passers on the queenside.
30...Nxd5 31.Bxd5 Bxd5 32.Rxd5 Rxb6 33.Rxh5 Rb3?!
This move gets an exclamation mark in ChessBase's 2021 Mega database, although it is not clear if that is from Kasparov or an anonymous ChessBase annotator. Better seems to be 33...Bxb4+ 34.Nxb4 Rxb4, when the engines reckon White's best plan is to offer the pawn back with 35.Kd2!?
34.Kd2 b5 35.h4 Rc8 36.g4?
Trying to create a passed pawn on the kingside, but this is the wrong way to go about it. The engines reckon 36.Rg5 is much less clear, eg 36...g6 37.g4 Kf6 (stopping h5) 38.Nc5 Bxc5 39.Rxc5 Rxc5 40.dxc5, which seems very drawish, but is not forced.
Definitely wrong, however, is trying to activate the passed d pawn starting with 36.e4? as 36...Rc4 is impossible to successfully meet, eg 37.Ke3 Rcc3 38.Rd1 a3, or 37.Rd5 a3 38.e5 Bb4+ Rcxb4, when in each case White's pieces are too uncoordinated for stopping Black's queenside pawns.
36...a3 37.f4
It is too late for 37.Rg5. Black can ignore it, eg 37...b4 38.Rxg7 Rxd3+! 39.Kxd3 b3 etc.
37...Rcc3
The notes in Mega21 reckon even stronger is 37...Rc4!?, eg 38.Rd5 e6 39.e4 Rcc3 40.Rxd6+ Kxd6 41.Nc5 Rxc5 42.e5+ Rxe5 43.dxe5+ when material is level but Black's advanced queenside pawns and more-active pieces give a large advantage.
38.Rd5 Ke6 39.Rh5 b4?!
The engines' 39...Rc4 looks stronger.
40.Ra5 Rxd3+?!
The less-promising way to sac the exchange. Stockfish12 gives 40...Rb2+ 41.Nxb2 Bxf4+ 42.e3! (42.Kd1 axb2) Bxe3+ 43.Ke2 axb2 44.Rb1, which is also given in Mega21 via a transposition. After the further moves 44...Bc1 45.Rb5 b3 46.h5 there is an equal sign in Mega21, but the engines' 46...f6! puts White more-or-less in zugzwang, eg 47.Rf5 Bh6! as 48.Rxb2 fails to 48...Rc2+, and 47.Rc5 is met by 47...Rxc5 48.dxc5 Kd5 49.Kd3 Kxc5 50.Kc3 Kd5 51.Kd3 Ke5 etc.
41.exd3 Bxf4+ 42.Ke2 Rc3
42...Rb2+ 43.Kf3 is equal, according to the engines.
43.g5 Bc1 44.h5 b3 45.R5xa3
A possibly simpler way to a draw is the engines' 45.h6!? gxh6 46.gxh6 b2 47.h7 Rc2+ 48.Kf3 Rh2 49.Rh2 Rb1 50.Rxh7 Rxa3.
45...Bxa3 46.Rxa3 b2 47.Ra6+ Kf5 48.Rb6 Rc2+ 49.Ke3 Kxg5 50.d5 Kxh5 51.Kd4?!
More accurate may be 51.Ke4, the point being the king has more influence on the kingside. If, as in the game, 51...g5 then 52.d4 is dead-equal, according to the engines, eg 52...g4 53.d6 Rc6!? Rb5+. And if 51...Re2+ then 52.Kf5 seems fine, eg 52...g6+ 53.Kf6 Rf2+ 54.Ke7 g5 55.d6, which the engines reckon is still dead-equal.
The notes in Mega21 point out 51.d6? runs into 51...Rc6! (52.Rxb2 Rxd6 is a tablebase win for Black).
51...g5 52.Rb8 g4 53.d6 Rc6 54.Ke5 Rc5+ 55.Kf6
55.Ke4!? also seems to draw, eg 55...f5+ 56.Kd4 Rc8!? 57.Rxc8! b1=Q 58.d7, when Black has to settle for perpetual check.
55...g3 56.Rxb2 Rd5 57.Kxf7 Rxd6 58.Rd2 Kg4 59.d4 Kf5!? 60.Ke7 Rd5 61.Rd3 Kf4 62.Ke6 Rg5 63.d5?
Tablebases show White draws with 63.Rd1, eg 63...g2 64.Rg1 Ke3 65.Rxg2!?
63...Rg6+! 64.Ke7 g2 65.Rd1 Ke5!
Another only move.
66.d6 Re6+ 67.Kd7 Rxd6+ 68.Rxd6 g1=Q
The game finished:
69.Re6+ Kf5 70.Rd6 Qa7+ 71.Kd8 Ke5 72.Rg6 Qa5+ 73.Kd7 Qa4+ 74.Ke7 Qh4+ 75.Kf8 Qd8+ 76.Kf7 Kf5 77.Rh6 Qd7+ 78.Kf8 Kg5 0-1
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