Chess Openings Lab
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Blackmar-Diemer Gambit Declined: Vienna Defense

The Vienna Defense is 4...Bf5, guarding the e4 pawn with the bishop instead of taking on f3. White can win the pawn back with fxe4 or chase the bishop with g4, while Black counts on quick counterplay against c2 and the queenside.

Moves
1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 Bf5
ECO
D00
Engine
−0.66 · a slight edge for Black (Stockfish 17.1, depth 20)
Played
778 games in our lichess sample
White scores
49.4%

Key ideas for both sides

White

  • 5.fxe4 Nxe4 6.Qf3 is the main idea: the queen attacks the e4 knight and the f5 bishop together.
  • After 6...Nxc3 7.bxc3 Bxc2, White has given a pawn for the half-open b-file and quick development with Nh3.
  • 5.g4 chases the bishop to g6, then g5 drives away the f6 knight and Nxe4 wins the pawn back.
  • 5.Bg5 is solid: fxe4 and Nf3 follow, aiming to recover the pawn with simple development.

Black

  • Against 5.fxe4, take with the knight and meet 6.Qf3 with 6...Nxc3, then pick up c2 with the bishop.
  • Against 5.g4, retreat to g6 and use ...Nd5 and ...h6 to hit the advanced g5 pawn.
  • ...e6 and ...Nbd7 support the f5 bishop and the e4 pawn in the quieter lines.

Plans and pawn structure

In the 5.fxe4 line, the position opens fast. White gets a broken queenside after bxc3 but uses the open f-file, the b-file and the queen on f3 against b7 and f7. Black has the c2 pawn and must finish development with ...e6, ...Nd7 and castling. In the g4 lines, White grabs kingside space and Black aims ...h6, ...Nb6 and ...e6 against the overextended pawns.

Where the engine's main line heads: White pawn d4, no e-pawns for White, no d-pawn for Black. White has a pawn on d4 and no e-pawn; Black has no d-pawn. White has more central space; Black's pieces are free and the d4 pawn is a target.

What the engine plays from here

Stockfish 17.1 at depth 20 rates the position −0.66: a slight edge for Black. Its three top choices for White:

  1. −0.66 5.fxe4 Nxe4 6.Qf3 Nxc3 7.bxc3 Bxc2
  2. −0.68 5.g4 Bg6 6.g5 Nd5 7.Nxe4 h6
  3. −0.82 5.Bg5 Nbd7 6.fxe4 Nxe4 7.Nxe4 Bxe4

Pawns, from White's side.

How it scores on lichess

778 rated lichess games reached this position; White scored 49.4%.

under 120043.6%
1200–159950.0%
1600–199951.0%
2000 and up47.1%

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

How to play against it

Choose between 5.fxe4 and 5.g4 and play it with energy. After 5.fxe4 Nxe4 6.Qf3, accept that c2 falls and use the time for Nh3, Bd3 and castling. Do not drift with quiet moves, because the f5 bishop then holds e4 and you remain a pawn down. White scores 49.4% overall here.

Questions

What are the moves of the Blackmar-Diemer Gambit Declined: Vienna Defense?

The Blackmar-Diemer Gambit Declined: Vienna Defense starts 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 Bf5. Its ECO code is D00.

Is the Blackmar-Diemer Gambit Declined: Vienna Defense good for Black?

Stockfish 17.1 rates the position −0.66 at depth 20, which is a slight edge for Black. In 778 lichess games from our sample, White scored 49.4%. A fighting choice for Black that needs accurate follow-up after Qf3; White must be willing to sacrifice c2 for activity.

What is the main idea of the Blackmar-Diemer Gambit Declined: Vienna Defense?

Black uses the light-squared bishop to defend e4 and stays a pawn up for now. White regains the pawn with fxe4 or by chasing the bishop with g4, and the game turns sharp with chances for both sides.

What should White play next?

The engine's first choice is fxe4, with g4 and Bg5 close behind. 5.fxe4 recovers the pawn, and after ...Nxe4 the queen comes to f3 to hit both the knight and the f5 bishop.

Updated October 2026. Sources and method.