Sicilian Moscow 3...Nc6 4.O-O Bd7

Sicilian: Moscow 3...Nc6 4.O-O Bd7

Definition

The move sequence 1. e4 c5 2.Nf3 d6 3.Bb5+ Nc6 4.O-O Bd7 constitutes a branch of the Moscow Variation of the Sicilian Defence. After White’s check on move three, Black blocks with the knight instead of the more common 3…Bd7, and answers the short castling 4.O-O with 4…Bd7, challenging the Bb5 and steering play toward flexible, strategically balanced middlegames.

Typical Move Order

Standard sequence leading to the position:

1. e4   c5
2. Nf3  d6
3. Bb5+ Nc6
4. O-O  Bd7

Strategic Significance

• Piece Play: By interposing the knight on c6, Black keeps the dark-squared bishop on c8 flexible. The later …g6 & …Bg7 setup is common.
• Pawn Structure: Unlike many Open Sicilians, the central tension (e4 vs. d6–c5) remains intact because White has not played d4 yet.
• Tempo Considerations: White’s Bb5+ often trades for the c6-knight, inflicting double pawns after …bxc6. By playing 3…Nc6 first, Black invites this trade on improved terms—Black can recapture with the bishop (…Bxc6) or avoid structural damage with …g6.
• Flexibility for Black: The immediate 4…Bd7 signals a willingness to recapture on c6 with the bishop. Black can transpose to Scheveningen, Dragon, or Classical structures according to White’s choices.
• Simplified Theory: Compared with the sharp Najdorf or 3…Bd7 Moscow, the 3…Nc6 line is slightly less theoretical, attractive to players seeking solid yet dynamic play.

Plans for White

• Trade on c6 followed by c3 & d4, aiming for an improved Alapin-style structure.
• Maintain the bishop with 5.Re1, 6.c3, and 7.d4 (Galjoust plan), keeping pressure on e5-squares.
• Prepare an English Attack setup: 5.c3, 6.d4, 7.Be3, 8.Qe2 and possibly c2-c4.

Plans for Black

• …Nf6, …e6, and a Scheveningen pawn shield (…a6 often reserved for later).
• …g6 & …Bg7, morphing into a Dragon-like formation where White’s bishop trade weakens Black’s queenside light squares less than usual.
• Queenside counterplay with …Rb8 and …b5 after the bishop trade, exploiting the semi-open b-file.

Historical & Theoretical Notes

While the Moscow Variation (3.Bb5+) gained popularity in the 1980s as an anti-Najdorf weapon, the specific 3…Nc6 4…Bd7 system surged in the early 2000s, adopted by elite grandmasters such as Peter Leko and Sergey Rublevsky to sidestep deep Najdorf preparation.

A famous early outing occurred in the match Leko – Kramnik, Dortmund 2003, where Kramnik equalized comfortably and demonstrated the robustness of the line for Black.

Illustrative Game

Rublevsky vs. Svidler, Russian Ch. Superfinal, Moscow 2007

Interesting Facts

• In many databases the line is catalogued as B51, though some sources split it between B50 and B53 depending on when …a6 is played.
• Because White castles on move four, opposite-side castling is possible if Black later chooses …O-O-O, leading to lively pawn storms on opposite wings.
• Engines rate the resulting positions around 0.00 to +0.20 for White—slightly more balanced than most Open Sicilians, which typically favor White by +0.30 to +0.40.

Practical Tips

• For White: Decide early whether you intend to trade on c6. If you keep the bishop, avoid allowing …a6 & …b5 where the bishop can be chased to an awkward square.
• For Black: Memorize key transpositions: after 5.Re1, …Nf6 6.c3 a6 sidesteps immediate structural damage; against 5.c4, react with …Nf6 and …g6, letting the bishop capture on c6 when it suits you.