Pirc - Holmov system
1. e4 d6 2. d4 Nf6 3. Nc3 g6 4. Bc4
White moves the king's pawn to e4. Black plays the queen's pawn to d6. White advances the queen's pawn to d4.
Black develops the knight to f6. White develops the knight to c3. Black plays the g-pawn to g6.
White develops the light-squared bishop to c4.