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Tuesday, September 25, 2012

Combating Anti-Sicilians with ..e5: Anti-Rossolimo

This post is a continuation in a larger series, providing here some opening analysis, statistics, and games. Please see the previous post for an introduction to the topic of meeting the Anti-Sicilians with an immediate …e5

1.e4 c5 2.Nf3 Nc6 3.Bb5 e5

White has several plans in this position. They can try to exploit the d5 square with Nc3, or the d6 and d5 squares with Na3-Nc4, possibly followed by Nc4-e3-d5. They can try to achieve the pawn break c3 and d4, hoping for a trade that will undermine Black's structure. Some players will attempt to trade on c6, and others still will rely on a slight lead in development by playing O-O, delaying selection of one of the above plans until Black commits.

Out of 259 games starting from this position, White scores ~61% (128 wins, 58 draws, and 73 losses). A more telling statistic, however, is the average rating of each player and their performance; if the White players from this sample are consistently stronger, then it is to be expected that the will win more often.

Average ratings and performance

White rating: 2285 (200 games); White performance: 2330 (59% vs 2265)
Black rating: 2265 (195 games); Black performance: 2190 (37% vs 2285)

The performance differential is also in White's favor. One should keep in mind, however, that this is still a fairly small sample size of games, and even if the statistics are unfavorable, it doesn't indicate that the line is unplayable. Furthermore, quite of number of the Black losses occur late in the game, after Black has already equalized (that assessment is my own, coupled with confirmation from SCID's engine).

You can download the full SCID opening report (in PDF format), which includes a theory table, as well as the PGN file containing the games. In addition, I've condensed the lines presented here (with annotations) into one single PGN file, available for download.

In most of the variations below, I will include statistics and reports on those specific lines, despite the fact that the small sample size for some makes them almost meaningless. Again, keep in mind that statistics aren't everything.

These variations will be split up into 4 different sections:
A) Miscellaneous 4th moves from White
B) 4.Bxc6
C) 4.c3
D) 4.O-O

This is my first large analysis post, and so you can expect updates to the lines (as mistakes are found) as well as updates to the format. Read ahead, and make sure you check back often!

A) Miscellaneous 4th moves from White

A1) 4.Nc3 Trying to take advantage of the weakened d5 square.
Download the full Opening Report for this variation

A2) 4.Na3 
Trying to take advantage of the weakened d6 square

A3) 4.d3 
Playing for a sort of King's Indian Attack, which actually should be a poor choice here since play has achieved ..e5. Normally, the KIA makes the most sense against Black setups where ..e6 was played, since it will cost Black a tempo to push to e5. However, 4.d3 also does contain a threat; now Black must increase the defense of the e5 pawn. Download the full opening report.

A4) 4.b4 
Is it an attempt to gain time for c3 and O-O, or to gain better control of d4? Regardless if this move is imitating the Evans, Benko, or Wing (Sicilian) gambit, it doesn't bring White much except for a material deficient. 

B) 4.Bxc6

I don't believe this move gives white much hope of an advantage. Compared to the exchange Ruy Lopez, Black has played the more useful ..c5 (rather than …a6, which here would just weaken the b6 square). White will have a hard time achieving the d4 break in any meaningful way. Just like the Ruy Lopez Exchange, this move doesn't threaten to win a pawn: 4.Bxc6 dxc6 5.Nxe5 fails to Qd4, among other moves, when the Pawn is recovered with a good game.

Out of 45 games with this move, the score is almost even, 18 White wins, 10 draws, and 17 Black wins. Download the full Opening Report.

Average ratings and performance
White rating: 2217 (38 games); White performance: 2266 (53% vs 2245)
Black rating: 2245 (37 games); Black performance: 2188 (46% vs 2217)

B1) 4…dxc6


B2) 4…bxc6

C) 4.c3

With 4.c3, White is trying to defy Black's clamp on d4 and push his pawns there anyway. Black needs to be careful to be able to meet d4 is a satisfactory way. In most cases where White is able to achieve d4, I would not recommend exchanging, even if it wins a pawn. Such an exchange or capture would leave Black with a damaged pawn structure, and would make it difficult to finish their development (unless one or both d-pawns are returned to White). This theme was mentioned in the introduction post.

Out of 24 games with this move, the score is exactly even, 8 White wins, 8 draws, and 8 Black wins. Download the full Opening Report.

Average ratings and performance
White rating: 2297 (18 games); White performance: 2196 (42% vs 2253)
Black rating: 2253 (18 games); Black performance: 2276 (47% vs 2297)

C1) 4…Nf6

The most natural move, played to put pressure on e4 and stop an effective d4 from White. This is a standard reply against the c3 move, since Nc3 is now impossible from White.

C2) 4…d6

Not only does this move protect the c5 and e5 pawns, but it also allows for development of the light-squared Bishop on c8. Still, it seems to me to be on the slow side, and does little to prevent problems on the D-file.

C3) 4…Bd6

The idea behind this move is twinfold: first, to provide additional support to e5, and secondly to block the d-file in an event of an exchange of pawns, thereby preventing a trade of Queens (as opposed to playing 4..d6).

C4) 4…Nge7

A simple move, to support Nc6. Also, the best scoring move in practice.

D) 4.O-O

By playing 4.O-O, White is now threatening to win the e5 pawn (Analogous, in some ways to 5.O-O in the Exchange Ruy Lopez). A slow move like 4..g6 is met with 5.Bxc6 dxc6 6.Nxe5, when Black has simply dropped a pawn since 6..Qd4 fails to 6.Nf3 Qxd4 7.Re1 when the Queen is lost.

Therefore, Black needs to increase the defense e5. There are several ways to do this: Nge7, d6, Bd6, and Qc7. Of these, I recommend Bd6, since it provides immediate defense to e5, which is important in the case of a quick c3 and d4 from White, as well as preparatory for ..a6. In response, White can choose to enter positions similar to the ones covered above, with 5.Na3, c3, or Bxc6. This sometimes results in direct transpositions, although in all of these lines Black must take care not to pile his/her pieces on the e-file.

One alternative that Black has to the defense of e5 is 4…Nd4, which is similar to a Bird's Defense to the Ruy Lopez, with the moves c5 and O-O inserted for Black and White, respectively. Together with 4…Bd6, these seem to me to be the most effective tries for Black.

Out of the 175 games with this move, the score is in White's favor, with 93 White wins, 36 draws, and 46 Black wins. Statistically, this appears to be White's best line. Download the full Opening Report.

Average ratings and performance
White rating: 2310 (132 games); White performance: 2371 (63% vs 2276)
Black rating: 2276 (130 games); Black performance: 2193 (34% vs 2310)

D1) 4…Nge7

This move is perhaps a bit slower than 4…Bd6, discussed below, but it does have some merit. Nge7 is the only move given for Black in "The Chess Advantage in Black and White" by Larry Kaufman, as a side variation in Game 1 of his Rossolimo chapter (Written from the perspective of the White player). The two lines from that source go as follows:

D2) 4…d6

In light of White's superior development and control of the light squares, this move strikes me as simply too passive and too slow. White is likely to emerge with some advantage.

D3) 4…Qc7

This move invites Nc3-d5 tactics from White, and is probably an unnecessary vulnerability.

D4) 4…Nd4

Taking advantage of White's exposed Bishop. Notice that in some of the other lines, involving Na3 or Nc3, this move just drops a pawn (and that 4.c3 makes this reply impossible.)

D5) 4…Bd6

I think this move is best, as it quickly develops, discourages opening of Black's d-file (through an exchange on c6), and protects both c5 and e5. Black should be able to get castled, move the Bishop and then play d6 or d5 at the right moment.

D5A) 5.Na3

D5B) 5.c3 and 5.Nc3


I think that this Anti-Rossolimo line with 3..e5 is playable for Black, perhaps even at higher levels. As a surprise weapon, it is a decent choice. It may be a bit on the slow side, and Black may need to work a little harder to generate winning chances from his slightly passive position, but I don't believe White can prove an advantage against this line. As pointed out in the introduction post, there are psychological benefits to this line as well.

Black does need to watch out for a few early pitfalls. In particular I think that the lines that involve an early Nc3, rather than c3 and d4, are more difficult to play against. Both sides typically deploy the same two or three moves, but move order may be important. Hopefully, the analysis present here will allow the second player to navigate away from the inferior lines.

These lines, especially the inferior variations, are also instructive. In particular, the way White tries to exploit d5 and d6, and undermine the Black pawn structure with c3 and d4, require alert maneuvers by Black. Some of the lines also contain interesting tactics worth noting.

I welcome any comments and suggestions. If you think you have found a flaw in my analysis, or you disagree with the evaluations, please post in the comments section. The idea behind this and future posts is to shed some light on this obscure lines.

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