Blackmar-Diemer Gambit

What is the Blackmar-Diemer Gambit?

The Blackmar-Diemer Gambit arises after 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3. In the main line, 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3, you have given a pawn for a lead in development, the half-open f-file and quick attacking chances against the black king. It is a sharp, open gambit with a devoted club following; at master level it is regarded as objectively dubious, but it is dangerous in practice because Black must find accurate moves early.

Main ideas and plans

Your standard set-up is Bd3 or Bc4, O-O, Ne5 or Bg5, and the queen transfer from e1 to h4, with your rooks on the f-file. Against the Bogoljubow Defense, 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3 g6, you usually play Bc4 and O-O, then bring the queen to e1 (the Studier Attack) and on to h4, aiming for Bh6 to trade the defending bishop; the Mad Dog Attack pushes the h-pawn at once instead. Against the Euwe Defense, 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3 e6, Black builds a solid French-like wall, and you play Bg5, Bd3 and O-O with ideas of Ne5 and Qe1-h4.

The Teichmann Defense aims to remove the f3-knight: after 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3 Bg4 6.h3 Bxf3 7.Qxf3 c6 you have the bishop pair and open lines, and the main choices are Be3 (the Classical Variation), g4 (the Seidel-Hall Attack) and Qf2. The Ziegler Defense with ...c6 is one of Black's most solid replies. Black can also decline on move four with ...e3, ...e6, ...c6 or ...Bf5, and in the Ryder Gambit you recapture on f3 with the queen and offer the d4 pawn as well.

Who is it for?

The BDG suits aggressive players who enjoy sacrificing material for the initiative, especially in blitz and rapid. The risks are clear: if Black defends calmly and returns the pawn at the right moment, you can end up simply a pawn down, and many opponents avoid it with 1.d4 d5 2.e4 c6, a Caro-Kann, or 1.d4 d5 2.e4 e6, a French. Be ready for the Lemberger Countergambit, 1.d4 d5 2.e4 dxe4 3.Nc3 e5, as well. Learn the standard Qe1-h4 attack first, then the plans against the Teichmann, Euwe and Bogoljubow.