Beat The ... Spanish

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.

Players have been puzzling over how to beat the Spanish: 1.e4 e5 2.Nf3 Nc6 3.Bb5 for centuries.

Black's most-popular reply is 3...a6, but it scores a somewhat disappointing 44% in Mega21.

However, this is quite a lot better than the 41% of 3...Nf6, 3...Bc5 and 3...Nge7, and well above the 39% of 3...Nd4 and the 32% of 3...d6.

Doing much better than these moves is 3...f5 with 47%, but statistically best with 49% is 3...g6!?

Position after 3...g6!?

White has three popular continuations, and two others that have been played by grandmasters and feature more than 100 times in Mega21.

A) 4.0-0 (1,820 games)

After 4...Bg7 the line splits.

A1 5.c3 a6!?, after which the line splits again.

A1.1 6.Ba4 Nge7 7.d4 exd4 8.cxd4 b5, when A1.1a 9.Bb3 Na5!? 10.Bc2 d6 scores 67% for Black and A1.1b 9.Bc2 0-0 10.d5 Na5 11.Nc3 d6 12.Nd4 Bb7 scores 75% for Black.

A1.2 6.Bxc6 dxc6 7.d4 exd4, when A1.2a 8.cxd4 Ne7 scores 56% for Black, albeit from a small sample, and A1.2b 8.Nxd4 Nf6 scores 100% for Black, albeit from a very small sample (8...Ne7 also scores 100%, but ...Nf6 is preferred by my main analysis engines Stockfish13 and Komodo12.1..1).

A1.3 6.Bc4!? b5 scores 67% for Black, albeit from a very small sample.

A2 5.Re1 a6!? 6.Ba4 d6 scores 67% for Black, albeit from a small sample.

A3 5.d3 Nge7, after which the line splits again.

A3.1 6.Nc3 h6!? 7.Be3 0-0 scores 61% for Black, albeit from a small sample.

A3.2 6.Bg5 h6, when A3.2a 7.Be3 0-0 scores 50% for Black, albeit from a small sample, and A3.2b 7.Bh4 0-0 scores 100% for Black, albeit from a very small sample.

A3.3 6.c3 a6!? 7.Ba4 0-0, when A3.3a 8.Re1 b5 scores 68% for Black and A3.3b 8.Nbd2 gives a position in which Black scores 57% with both 8...d6, which is Stockfish13's choice, and 8...d5, which is preferred by Komodo12.1.1.

A3.4 6.Be3 a6!? scores 100% for Black, albeit from a very small sample.

B) 4.c3 (1,758 games)

After 4...a6!? the line splits.

B1 5.Ba4 Bg7, after which the line splits again.

B1.1 6.d4 exd4 7.cxd4 b5, when B1.1a 8.Bb3 Na5 9.Bc2 Ne7 scores 79% for Black, albeit from a small sample, and B1.1b 8.Bc2 d5!? scores 54% for Black, albeit from a small sample.

B1.2 6.0-0 Nge7 is a transposition to A1.1.

B2 5.Bc4 Bg7 6.d4 exd4 7.cxd4 d6 scores 61% for Black, albeit from a small sample.

B3 5.Bxc6 dxc6, after which the line splits again.

B3.1 6.d4 exd4, when B3.1a 7.cxd4 Bg4!? scores 56% for Black and B3.1b 7.Qxd4!? Qxd4 scores 55% for Black, albeit from a small sample.

B3.2 6.Nxe5 Qg5 (this and 6...Qe7 score equally well, but the engines prefer 6...Qg5) 7.d4 Qxg2 8.Qf3 Qxf3 9.Nxf3 Nf6 scores 87% for Black, albeit from a very small sample.

C) 4.d4 (1,558 games)

After 4...exd4 the line splits.

C1 5.Bg5 Be7 6.Bxe7 Qxe7, after which the line splits again.

C1.1 7.Bxc6 dxc6 8.Qxd4 Nf6 9.Nc3 Bg4, when C1.1a 10.Nd2 c5 11.Qe3 0-0-0 12.h3 Bd7 13.0-0-0 Rhe8 scores 75% for Black, albeit from a very small sample, and C1.1b 10.0-0-0 Bxf3 11.gxf3 0-0 12.Qe3 Nh5!? scores 57% for Black, albeit from a small sample.

C1.2 7.0-0 Nf6, when C1.2a 8.e5 Nd5 scores 57% for Black and C1.2b 8.Bxc6 dxc6 9.Qxd4 c5 10.Qe3 Bd7!? scores 75% for Black, albeit from a very small sample.

C2 5.Nxd4 Bg7 6.Be3 Nf6 7.Nc3 0-0, after which the line splits again.

C2.1 8.0-0 Ne7!? scores 60% for Black from 25 games but the sample sizes immediately shrink because White has tried 12 different replies.

C2.2 8.f3 Ne5!? scores 100% for Black, albeit from a very small sample.

C3 5.c3!? a6!?, after which the line splits again.

C3.1 6.Bc4 b5 7.Bb3 Bg7 8.cxd4 is a transposition to B1.1a.

C3.2 6.Ba4 Bg7 7.cxd4 is a transposition to B1.1.

C3.3 6.Bxc6 dxc6 is a transposition to B3.1.

D) 4.Nc3 (166 games)

After 4...Bg7 the line splits.

D1 5.d3 h6!? 6.Be3 results in a position that occurs only six times in Mega21. The highest-rated player to reach it won with 6...Nd4!?, which is the choice of the engines.

D2 5.0-0 a6, after which the line splits again.

D2.1 6.Ba4 Nge7 7.d3 h6!? scores 75% for Black, albeit from a small sample.

D2.2 6.Bxc6 results in a position that occurs only four times in Mega21. The engines like 6...dxc6, although the highest-rated player to reach it won with 6...bxc6!?

D2.3 6.Bc4 results in a position that occurs only three times (with Black to move) in Mega21. The engines like 6...d6, although the move lost the one time it was played.

E) 4.Bxc6 (148 games)

After 4...dxc6 the line splits.

E1 5.0-0 Bg7, after which the line splits again.

E1.1 6.d3 c5!? scores 80% for Black, albeit from a small sample.

E1.2 6.b3 Ne7 scores 83% for Black, albeit from a very small sample.

E2 5.d4 exd4 6.Qxd4 Qxd4 7.Nxd4 Bg7, after which the line splits again.

E2.1 8.c3 Bd7 9.Be3 c5 scores 87% for Black, albeit from a very small sample.

E2.2 8.Ne2 results in a position that occurs only 14 times in Mega21. The engines like 8...f5!?, which won the only time it was played.

E3 5.d3 Bg7 reaches a position in Mega21 in which White has tried seven moves, none more than six times. Most popular is 6.Nbd2, to which Black has replied with six different moves and never lost. Stockfish13 suggests 6...c5, while Komodo12.1.1 likes 6...Nh6 and 6...f6!?