Blackmar-Diemer Gambit (BDG)

Blackmar-Diemer Gambit (BDG)
	a b c d e f g h 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1 a b c d e f g h
	Position in Forsyth-Edwards Notation (FEN) rnbqkbnr/ppp1pppp/8/8/3Pp3/2N5/PPP2PPP/R1BQKBNR b
	Moves: 1. d4 d5 2. e4 dxe4 3. Nc3

3. Nc3

White has brought his minor piece into action and taken control of the middle. Simultaneously, he has put pressure on Black's e4-pawn, which Black must now try and defend. Nf6 or Bf5 would most commonly be used to defend the lone pawn, while e5 gives the option of a pawn transfer. f5 defends the pawn using Black's f-pawn, a less optimal response. Rarer responses include Nc6 transposing to the Nimzowitsch Defense and adding an attacker to the d4 pawn, and c5, a rather unexplored countergambit.

Theory table

.

1. d4 d5 2. e4 dxe4 3. Nc3

	3	4	5	6	7
Main line	... Nf6	f3 exf3	Nxf3 g6	Bc4 Bg7	O-O O-O	⩱
Lemberger Countergambit	... e5	dxe5 Qxd1+	Kxd1 Nc6	Nxe4 Nxe5	=
Zeller Defense	... Bf5	f3 –	=
Netherlands Variation	f5	Bg5 Nf6	=
Reversed Albin Countergambit	c5	d5 Nf6	=