Queen's Indian - Marienbad system
1. d4 Nf6 2. Nf3 b6 3. g3 Bb7 4. Bg2 c5
White advances the queen's pawn to d4. Black develops the knight to f6. White develops the knight to f3.
Black advances the b-pawn to b6. White pushes the g-pawn to g3. Black develops the light-squared bishop to b7.
White develops the light-squared bishop to g2. Black advances the c-pawn to c5.