Chess Openings Lab
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Slav Defense: Bonet Gambit

The Bonet Gambit is 3.Nf3 Nf6 4.Bg5, developing the bishop to g5 while the c4 pawn is left without a defender. Black can take on c4 and hold it with ...b5, while White hopes development and pressure on the queenside chain make up for the pawn.

Moves
1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Bg5
ECO
D11
Engine
−0.49 · a slight edge for Black (Stockfish 17.1, depth 20)
Played
388 games in our lichess sample
White scores
54.1%

Key ideas for both sides

White

  • After 4...dxc4, play 5.e3, 6.Be2 and 7.O-O, castling before trying to win back the pawn.
  • Against 4...Ne4, retreat with 5.Bf4 and be ready for the ...e5 strike.
  • Use Nbd2 and a4 to attack the b5 pawn once Black has committed to holding c4.
  • The g5 bishop can take on f6 to damage Black's kingside pawns if that helps.

Black

  • 4...dxc4 is the engine's top move: grab the pawn and support it with ...b5 and ...Bb7.
  • ...Ne4 hits the g5 bishop and prepares ...e5 to open the center.
  • ...e6 and ...Be7 end any worry about the f6 knight and finish kingside development.
  • ...h6 asks the bishop to decide, a useful move in many of these setups.

Plans and pawn structure

White gives up c4 for development. Black keeps it with ...b5, ...Bb7 and ...e6, then castles. White wants e3, Be2, O-O, Nbd2 and a4 to break the queenside chain, maybe with b3 too. If Black's chain holds, the extra pawn and queenside majority count in any ending. If White pries it open, the rooks reach the a- and c-files and Black's queenside gets loose.

What the engine plays from here

Stockfish 17.1 at depth 20 rates the position −0.49: a slight edge for Black. Its three top choices for Black:

  1. −0.49 4...dxc4 5.e3 b5 6.Be2 Bb7 7.O-O
  2. −0.29 4...Ne4 5.Bf4 e5 6.Bxe5 Nd7 7.Bg3
  3. +0.09 4...Qb6 5.Qc2 g6 6.c5 Qc7 7.Nc3

Pawns, from White's side.

How it scores on lichess

388 rated lichess games reached this position; White scored 54.1%.

1200–159952.7%
1600–199953.5%
2000 and up58.3%

Light: White wins. Grey: draws. Dark: Black wins. About the sample.

How to play against it

As Black, take on c4 and hold it with ...b5. The g5 bishop is not dangerous by itself; ...e6 and ...Be7 are enough to neutralize it. Avoid the slower 4...Qb6, which the engine rates well below the pawn grab. Castle short before you start any queenside action.

Questions

What are the moves of the Slav Defense: Bonet Gambit?

The Slav Defense: Bonet Gambit starts 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Bg5. Its ECO code is D11.

Is the Slav Defense: Bonet Gambit good for White?

Stockfish 17.1 rates the position −0.49 at depth 20, which is a slight edge for Black. In 388 lichess games from our sample, White scored 54.1%. An offbeat choice for White that suits players who like a lead in development; a Black player who knows how to hold c4 is comfortable.

What is the main idea of the Slav Defense: Bonet Gambit?

White develops the bishop to g5 and leaves the c4 pawn hanging. Black takes it and keeps it with ...b5, while White develops and attacks the queenside chain with a4.

What should Black play next?

The engine's first choice is dxc4, with Ne4 and Qb6 close behind. 4...dxc4 takes the pawn, and Black plans to keep it with ...b5 and ...Bb7.

Updated October 2026. Sources and method.