Black develops his light Queen's Bishop to
K3(e3) improving the defence of his threatened
QP. White's Queen to QKt3(b3) attacks Black's
dark bishop, to regain the pawn by 5..Kt-QB3, 6.P-QR3!
White Black
1. P-KKt3 P-K4
2. B-Kt2 P-Q4
3. P-QKt4 BxP
4. P-QB4 B-Q3
5. Q-Kt3