Dutch defence - Dutch-Indian (Nimzo-Dutch) variation
1. d4 f5 2. c4 Nf6 3. g3 e6 4. Bg2 Bb4+
White plays the queen's pawn to d4. Black plays the f-pawn to f5. White advances the c-pawn to c4.
Black develops the knight to f6. White moves the g-pawn to g3. Black advances the king's pawn to e6.
White develops the light-squared bishop to g2. Black develops the dark-squared bishop to b4, giving check.