Beat The ... Sicilian Sveshnikov

IN this series I am looking at the statistically best way to play against popular opening lines.

The numbers are drawn from the 2021 edition of ChessBase's Mega database, ignoring, where possible, those results that include very few games and so are statistically insignificant.

The Sveshnikov Variation of the Sicilian Defence: 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e5, formerly known as the Lasker-Pelikan, is popular at club and elite levels.

White's most-popular reply, 6.Ndb5, scores 54%, while the next three most-popular moves score 35% or less.

Position after 6.Ndb5

Black has three replies that occur more than 300 times each in Mega21.

A) 6...d6 (52,450 games)

Meeting this with the commonest response, 7.Bg5, is also the most successful statistically, keeping White's score at 54%, after which the line splits.

A1 7...a6 8.Na3, after which the line splits again.

A1.1 8...b5 9.Bxf6!?, when A1.1a 9...gxf6 10.Nd5 f5 11.g3 fxe4 12.Bg2 Be6 13.Bxe4 Bg7 14.Qh5 Rc8 15.Rd1 Ne7 16.Nxe7 Qxe7 17.0-0 scores 88% for White, albeit from a small sample, and A1.1b 9...Qxf6 10.Nd5 Qd8 11.c4!? scores 84% for White.

A1.2 8...Be6 9.Nc4, when A1.2a 9...Rc8 10.Bxf6 gxf6 11.Bd3!? Ne7 12.Ne3 Bh6 13.0-0 Bxh3 14.fxe3 Qb6 15.Qf3 scores 85% for White, A1.1b 9...Rb8 10.a4 Nb4 11.Ne3 scores 67% for White, albeit from a very small sample, and A1.1c 9...Nd4 10.Nd5!? Bxd5 11.exd5 scores 88% for White, albeit from a small sample.

A1.3 8...Be7 9.Nc4!?, when A1.3a 9...b5 10.Bxf6 gxf6 11.Ne3 scores 90% for White, A1.3b 9...Nd4 10.Bxf6 Bxf6 11.Nd5 b5 12.Ncb6 Rb8 13.Nxc8 Rxc8 14.c3 scores 83% for White and A1.3c 9...Be6 10.Bxf6 gxf6 11.Ne3 scores 87% for White.

A2 7...Be7 8.Bxf6, after which the line splits again.

A2.1 8...gxf6 9.Nd5, when A2.1a 9...0-0 10.Nxe7+ Qxe7 11.Qxd6 scores 87% for White and A2.1b 9...Rb8 10.Nbc7+ Kf8 11.Qh5 scores 78% for White.

A2.2 8...Bxf6!? 9.Qxd6!? Qxd6 10.Nxd6+ scores 92% for White, albeit from a small sample.

A3 7...Be6 8.Nd5!?, after which the line splits again.

A3.1 8...Rc8 9.Bxf6!? gaxf6 10.c3 scores 75% for White.

A3.2 8...Bxd5 9.exd5 Nce7 10.c3!? scores 100% for White, albeit from a small sample (note that 10...Nexd5?! runs into 11.Qa4!, when 11...Qd7? loses to 12.Nxd6+ Bxd6 13.Bb5).

B) 6...h6!? (561 games)

After 7.Nd6+ Bxd6 8.Qxd6 Qe7 9.Qxe7+ Kxe7 10.b3 d6 11.Ba3 the line splits.

B1 11...a6 12.0-0-0 Rd8 13.Nd5+ Nxd5 14.exd5, after which the line splits again.

B1.1 14...Nb8 15.Re1!? scores 63% for White, albeit from a small sample.

B1.2 14...Nd4 15.c3 scores 75% for White, albeit from a very small sample.

B2 11...Be6 12.0-0-0 Rhd8 13.f3!? a6 14.Nd5+ Bxd5 15.exd5 scores 75% for White, albeit from a small sample.

C) 6...a6!? (329 games)

After 7.Nd6+ Bxd6 8.Qxd6 Qe7 9.Qd1!? the line splits.

C1 9...d6 10.Be2!? Be6 11.0-0 scores 75% for White, albeit from a small sample.

C2 9...h6 10.Be3, after which the line splits again.

C2.1 10...0-0 11.Qd2!? scores 92% for White, albeit from a small sample.

C2.2 10...Qb4!? 11.a3, when C2.2a 11...Qe7 reaches a position in Mega21 in which White scores 100% with 12.Qd2, 12.Bc4 and 12.Be2, albeit from very small samples, C2.2b 11...Qa5 reaches a position in Mega21 in which White scores 100% with 12.b4 and 12.f4, albeit from very small samples, and C2.2c 11...Qxb2?? 12.Na4 scores 100% for White, albeit from a small sample.

C2.3 10...d6 11.Be2, when C2.3a 11...Be6 reaches a position in Mega21 in which White scores 100% with 12.0-0 and 12.Nd5, albeit from small samples, and C2.3b 11...0-0 reaches a position in Mega21 in which White scores 100% with 12.0-0 and 12.Qd2, albeit from small samples.

C2.4 10...b5 11.a4 b4 12.Nd5 Nxd5 reaches a position in Mega21 in which White scores 100% with 13.Qxd5 and 13.exd5, albeit from very small samples.

Bobby Fischer v The Sicilian (part seven)

Sicilian Sveshnikov

Fischer met 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e5 with the mainline 6.Ndb5 d6 7.Bg5.

Position after 7.Bg5

Black attacks the advanced knight with 7...a6

8.Bxf6!?

The main move is 8.Na3 but the text is a respectable alternative.

8...gxf6 9.Na3

A)

9...f5

Stockfish12's choice.

10.Bc4 Bg7?!

Critical seems to be 10...Qg5, when the main reply is 11.g3 but my main analysis engines prefer 11.Bd5 with an unclear position. One point of 11.Bd5 is that 11...Qxg2 can be met by 12.exf5 Qg5 13.Nc4 Bxf5 14.Bxc6+ bxc6 15.Nxd6+ Bxd6 16.Qxd6, when the engines reckon Black has to find 16...Rd8! 17.Qxc6+ Kf8! 18.Rd1 Kg7, after which Black's active pieces compensate for the pawn-minus, according to Komodo11.01, but Stockfish12 comes to prefer White.

11.Qh5 0-0

12.exf5 Nd4

13.Bd3

White had a large advantage, according to the engines, in Fischer - Andrew Soltis, Manhattan (New York) Blitz 1971 (1-0, 25 moves).

B)

9...d5!?

This is not as weird as it may appear at first sight.

10.Nxd5 Bxa3

11.bxa3

The point of Black's play, which was pioneered by Jorge Pelikán, is that White's queenside pawns are a mess.

11...Be6

12.Bc4 Qa5+

13.Qd2 0-0-0

A key moment. Pelikán preferred exchanging queens, 13...Qxd2+ 14.Kxd2, and then castling long, 14...0-0-0, although the queenless middlegame is slightly better for White, according to the engines.

14.Rd1 Qxa3

15.0-0

Black has regained his pawn but White has the safer king.

15...Rhg8

The engines prefer 15...f5!? but reckon White may be slightly better after 16.Qe2 (Stockfish12) or 16.exf5 (Komodo11.01).

16.Qe3!

Despite having the safer king, Fischer first more-or-less forces queens off ...

16...Qxe3

17.fxe3!

... and then recaptures in a way that activates his king's rook along the f file.

17...Kb8

Leonid Shamkovich - Alexander Jongsma, IBM Amsterdam 1968, saw 17...Rg4 18.Bd3 f5 19.Nf6 Rh4 20.exf5 Bxa2 21.Be4 with a large advantage for White, according to the engines (1-0, 47 moves).

18.Bb3!?

The straightforward 18.Rxf6 is also good for White.

18...Rg6 19.Nb6 Kc7 20.Rxd8 Nxd8 21.Nd5 Bxd5 22.Bxd5

White was better in Fischer - Héctor Rossetto, Buenos Aires 1960, according to the engines (1-0, 44 moves).

C)

9...b5

This is easily Black's most-popular response, but it was not faced by Fischer. The main line runs 10.Nd5 f5 11.Bd3 Be6 12.0-0 Bxd5 13.exd5 Ne7

More than 1,000 games have reached this position in ChessBase's 2020 Mega database.

White faces a major choice between grabbing a pawn by 14.Nxb5!?, which gives Black a strong initiative with 14...Bg7 (14...Nxd5? 15.Bxf5; 14...axb5?? 15.Bxb5+ Nc6 16.Bxc6+ Ke7 17.Bxa8) 15.Nc3 e4 (Stockfish12 gives Black full compensation, but Komodo11.01 prefers White), or playing less greedily, eg 14.c4 Bg7 15.Rb1 e4 16.Be2 (again Stockfish12 reckons Black is equal, but Komodo11.01 gives White a small edge).

Black develops the king's bishop with 7...Be7?

This is the most-popular alternative to 7...a6 - there are 274 examples of the move in Mega20 - but White wins a pawn by force.

8.Bxf6

A)

8...gxf6

9.Nd5 0-0

10.Nxe7+ Qxe7

11.Qxd6

Black has no compensation for being a pawn down.

B)

8...Bxf6

9.Nxd6+

Both 9...Ke7 and 9...Kf8 can be met by 10.Nxc8(+), when again Black has no compensation for a pawn.