Slav: 3.Nf3 Bg4

Slav: 3.Nf3 Bg4

Definition

“Slav: 3.Nf3 Bg4” is a branch of the Slav Defense that arises after the moves 1.d4 d5 2.c4 c6 3.Nf3 Bg4. By pinning the f3-knight at once, Black sidesteps the huge body of theory in the main line Slav (3…Nf6) and in the Semi-Slav (3…e6). ECO normally classifies the position under the code D11.

Typical Move Order & Starting Position

The critical tabiya appears after the first three moves:

Black’s dark-squared bishop stands outside the pawn chain, pinning the knight and influencing the e4-square.

Strategic Ideas

• For Black
  • Seize control of e4 and undermine White’s central expansion.
  • Decide whether to maintain the pin, exchange on f3 (doubling White’s pawns after gxf3), or retreat to h5/f5 once chased.
  • Avoid the traditional “bad Slav bishop” by developing it before …e6 or …e5 locks it in.
  • Choose a pawn structure: …e6 can transpose to a Semi-Slav set-up, while …dxc4 may head toward Meran-type positions.
• For White
  • Break the pin with 4.h3 or 4.Nbd2; or challenge it directly with 4.Qb3 or 4.Ne5.
  • Capture in the centre with 4.cxd5, arguing that the bishop on g4 is slightly misplaced when the position opens.
  • Exploit the two-bishop advantage if Black exchanges on f3 too early.
  • Prepare e2–e4 or minority-attack plans depending on the resulting pawn structure.

Common Continuations

1. 4.Ne5 Bf5 5.cxd5 cxd5 6.Qb3 White immediately questions the bishop and the b7-pawn. The game often transposes to Caro-Kann structures where Black’s queen may be slightly exposed.
2. 4.cxd5 Bxf3 5.gxf3 cxd5 Black gives up the bishop pair but gets a rock-solid Carlsbad pawn structure. White’s kingside pawn majority can become both a strength (attacking chances) and a weakness (king safety).
3. 4.e3 e6 5.Nc3 Nf6 6.h3 Leads to a classical Queen’s Gambit-style battle after 6…Bxf3 7.Qxf3, with balanced chances.
4. 4.Qb3 A direct attempt to punish 3…Bg4 by attacking both b7 and d5. Black may respond with 4…Qb6, 4…dxc4, or the ambitious 4…Nd7.

Historical Background

The line was explored in the 1920s by Akiba Rubinstein and later employed as a surprise weapon by players such as Salo Flohr and Samuel Reshevsky. Boris Gelfand and Alexander Morozevich occasionally revived it at elite level in the early 2000s, but the move 3…Bg4 has never matched the popularity of 3…Nf6. Its modern appeal lies in its ability to take an opponent out of well-trodden theory as early as move three.

Illustrative Games

Game 1 – Gelfand vs. Morozevich, Linares 2004

Gelfand’s precise play converted the bishop pair into a lasting edge, highlighting the long-term risks Black accepts.

Game 2 – Nakamura vs. So, U.S. Championship 2016 (blitz playoff)

A wild blitz skirmish showing how quickly the position can sharpen if Black keeps the bishop on g6 and White pushes g-pawns.

Interesting Facts & Anecdotes

• The line sometimes carries the informal nickname “Mikėnas Variation,” after Lithuanian grandmaster Vladas Mikėnas, who used it in the 1930s.
• Because the structure after 4.cxd5 can mirror the Caro-Kann Exchange Variation, some coaches recommend studying those endgames in parallel to understand the resulting pawn-majority play.
• In correspondence chess the move 4.Qb3 has scored above 60 %, suggesting that accurate defense is not trivial even with engine assistance.
• The early pin 3…Bg4 can transpose to the “Triangle System” (…e6 and …c6) or even the Cambridge Springs Queen’s Gambit (…Nf6, …e6, …Nbd7, …Qa5) depending on later choices—making it an excellent weapon for players who value flexibility.

When to Use 3…Bg4

Choose this variation when you:

• Want to leave mainstream Slav theory behind by move three.
• Feel comfortable playing with a slightly unbalanced bishop vs. knight scenario.
• Enjoy transpositional possibilities into Queen’s Gambit or Caro-Kann-type structures.

At the same time, be ready to defend the b7-pawn, handle the eventual loss of the bishop pair, and navigate tactical lines arising from pushes like g2–g4 or Ne5.