ECO A50 · Mexican Defense

Mexican Defense: Horsefly Gambit

1. d4 Nf6 2. c4 Nc6 3. d5 Ne5 4. f4

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Black to move. The arrow shows Stockfish’s best move.
Best move

4… Nxc4−0.59

Black is slightly better. Stockfish 18, depth 18.

Analyze this position

In the Mexican Defense: Horsefly Gambit (A50), reached after 1. d4 Nf6 2. c4 Nc6 3. d5 Ne5 4. f4, Stockfish 18 recommends 4… Nxc4 for Black. Black is slightly better (−0.59).

Top engine moves

  1. −0.594… Nxc4 5. e4 Nb6 6. Nc3 e6 7. dxe6 dxe6 8. Qxd8+ Kxd8 9. Bd2
  2. +0.274… Ng6 5. Nc3 e6 6. e4 Bb4 7. Bd3 e5 8. f5 Bxc3+ 9. bxc3
  3. +1.334… Neg4 5. h3 Nh6 6. g4 Ne4 7. Qd3 f5 8. Bg2 Nc5 9. Qe3

Frequently asked questions

What is the best move in the Mexican Defense: Horsefly Gambit?
After 1. d4 Nf6 2. c4 Nc6 3. d5 Ne5 4. f4, Stockfish 18 at depth 18 recommends 4… Nxc4 for Black, continuing 5. e4 Nb6 6. Nc3 e6 7. dxe6 dxe6 8. Qxd8+ Kxd8 9. Bd2. Black is slightly better (−0.59). The next best moves are 4… Ng6 (+0.27) and 4… Neg4 (+1.33).
Is the Mexican Defense: Horsefly Gambit a good opening?
Stockfish rates the position at −0.59: black is slightly better. Evaluations this early in the game are small, so practical results depend far more on knowing the plans and typical structures than on the engine's number.
What is the ECO code of the Mexican Defense: Horsefly Gambit?
A50. ECO codes classify chess openings from A00 to E99; A is the volume for flank openings.

Opening names from the Lichess opening book (CC0). Pieces by Colin M.L. Burnett (GPLv2+).