Mexican Defense: Horsefly Gambit

An entry in the Encyclopedia of Chess Openings (ECO A50), reached after 7 half-moves: 1. d4 Nf6 2. c4 Nc6 3. d5 Ne5 4. f4.

Black rook — Use ← → arrows or click moves to step through.

Black bishop — Use ← → arrows or click moves to step through.

End of this line

No further variations branch from this position in our database. To explore neighbouring ideas:

About this opening

Mexican Defense: Horsefly Gambit is an opening in the Encyclopedia of Chess Openings, classified under code A50. ECO group A (A00–A99) covers flank and irregular openings, including the English, Bird, Réti and Dutch defences. This particular variation is reached after 7 half-moves from the starting position, with the move sequence 1. d4 Nf6 2. c4 Nc6 3. d5 Ne5 4. f4.

It belongs to the Mexican Defense family. Within that family this is a sub-variation (the Horsefly Gambit line).

The opening sequence in prose form: 1.d4 Nf6, 2.c4 Nc6, 3.d5 Ne5, 4.f4. From this position the encyclopaedia records no further canonical continuations — practical play branches into unnamed transpositions or returns to the parent line for alternative ideas.