White's QKtPawn exchanges, removing the bishop on
QB3(c3), and he has to accept doubled QBPs. Black's QPawn removes White's doubled QBP on
QB5(c4), for a good 6.Q-R4+ch..Kt-QB3, 7.QxP..Kt-B3.
White Black
1. P-Q4 P-Q4
2. P-QB4 P-K3
3. Kt-QB3 B-Kt5
4. P-QR3 BxKt ch
5. PxB PxP