Modern defence - Averbakh system - Randspringer variation
1. d4 d6 2. c4 g6 3. Nc3 Bg7 4. e4 f5
White moves the queen's pawn to d4. Black moves the queen's pawn to d6. White plays the c-pawn to c4.
Black moves the g-pawn to g6. White develops the knight to c3. Black develops the dark-squared bishop to g7.
White plays the king's pawn to e4. Black advances the f-pawn to f5.