Queen's Indian - 4.Nc3 - main line
1. d4 Nf6 2. c4 e6 3. Nf3 b6 4. Nc3 Bb7 5. Bg5 h6 6. Bh4 Bb4
White plays the queen's pawn to d4. Black develops the knight to f6. White advances the c-pawn to c4.
Black advances the king's pawn to e6. White develops the knight to f3. Black pushes the b-pawn to b6.
White jumps the knight to c3. Black develops the light-squared bishop to b7. White develops the dark-squared bishop to g5.
Black plays the h-pawn to h6. White deploys the dark-squared bishop to h4. Black moves the dark-squared bishop to b4.