The Blumenfeld Countergambit is a chess opening characterised by the moves 3...e6 4.Nf3 b5 in the Benoni Defense arising after: or alternatively: In fact, as many as 30 different move orders are possible.

[1] The Encyclopaedia of Chess Openings sorts the Blumenfeld Countergambit under code E10 (1.d4 Nf6 2.c4 e6 3.Nf3).

The natural development of the bishops to b7 and d6, combined with the half-open f-file for a rook, tend to facilitate Black's play on the kingside.

White, on the other hand, will typically look to counter in the centre by playing e4 at some point, while their additional queenside pawn also offers them some initiative on that side of the board.

The opening is named after the Russian master Benjamin Blumenfeld, and was later played by World Champion Alexander Alekhine.