Semi-Slav Defense

Semi-Slav Defense

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
Moves	1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 e6
ECO	D43–D49
Parent	Queen's Gambit

The Semi-Slav Defense is a variation of the Queen's Gambit chess opening defined by the position reached after the moves:

The position may readily be reached by a number of different move orders. With Black advancing pawns to both e6 and c6, the opening resembles a mixture of the Orthodox Queen's Gambit Declined (QGD) and the Slav Defense.

Black is threatening to capture the white pawn on c4, and hold it with b7–b5. White can avoid this in a number of ways. About 80% of games continue 5.Bg5 or 5.e3: the former constitutes a sharp pawn sacrifice, while the latter restricts the dark-squared bishop from its natural development to g5. Other possible moves are 5.Qb3, 5.g3 and 5.cxd5, the last of which, after 5...exd5, leads to a line of the QGD Exchange Variation where White's early Nf3 enables Black's queen bishop to freely develop, which should give equality (ECO codes D43 and D45).

For the Semi-Slav the Encyclopaedia of Chess Openings designates codes D43 through D49.

The main line continues with 5...Nbd7. The bishop moves 5...Bd6 and 5...Be7 are seldom seen, as masters realized early on that at e7, the bishop was passively placed and does nothing to further one of Black's aims, the freeing move ...e5. The unusual move 5...a6 is considered solid for Black. Some sources call 5...a6 the "accelerated Meran".

The main variation of the Semi-Slav is the Meran Variation, 6... dxc4 7. Bxc4 b5 (ECO codes D46 to D49), when play usually continues with 8.Bd3, with 8.Be2 and 8.Bb3 less common alternatives. The line was first played in 1906 in the game Schlechter–Perlis. The variation takes its name from the town of Meran (Merano) in northern Italy. During a 1924 tournament in Meran, it was used successfully in the game Gruenfeld–Rubinstein. Gruenfeld adopted the same variation two rounds later against Spielmann, winning as well.Viswanathan Anand won two games with Black in his World Chess Championship 2008 match with Vladimir Kramnik. Black surrenders his outpost on d5, gaining a tempo for queenside space expansion by b7–b5. White will play in the center, leading to a rich, complicated game. These opposing strategies, with the ensuing keen play, have long made the Meran a favorite for enterprising players of either color. An example is Gligoric v Ljubojevic, Belgrade, 1979.