Blumenfeld counter-gambit
1. d4 Nf6 2. c4 e6 3. Nf3 c5 4. d5 b5
White plays the queen's pawn to d4. Black develops the knight to f6. White pushes the c-pawn to c4.
Black moves the king's pawn to e6. White develops the knight to f3. Black moves the c-pawn to c5.
White plays the queen's pawn to d5. Black moves the b-pawn to b5.