Reti - King's Indian attack - Yugoslav variation
1. Nf3 d5 2. g3 Nf6 3. Bg2 c6 4. O-O Bg4
White develops the knight to f3. Black plays the queen's pawn to d5. White advances the g-pawn to g3.
Black develops the knight to f6. White develops the light-squared bishop to g2. Black advances the c-pawn to c6.
White castles kingside. Black develops the light-squared bishop to g4.