The Blumenfeld Gambit is a chess opening characterised by the moves 3...e6 4.Nf3 b5 in the Benoni Defence arising after:
1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nf3 b5
1. d4 Nf6 2. c4 e6 3. Nf3 c5 4. d5 b5
Black sacrifices a wing pawn to establish an imposing centre with pawns on c5, d5 and e6. The natural development of the bishops to b7 and d6, combined with the 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 his additional queenside pawn also offers him some initiative on that side of the board.
The opening is named after the Russian master Benjamin Blumenfeld, and was later played by World Chess Champion Alexander Alekhine.
The opening position can also be reached via the Benko Gambit (1.d4 Nf6 2.c4 c5 3.d5 b5 4.Nf3 e6). Possible continuations are 5.dxe6 (Kan-Goldenov, 1946), 5.Bg5 (Vaganian-K. Grigorian, 1971), 5.e4, or 5.a4 (Rubinstein-Spielmann, 1922), with 5.Bg5 being most frequently seen when this Gambit is employed.
Queen's Pawn Game 3.Nf3