White's KB3(f3) knight removed Black's newly set KP on
K5(e5), rejecting a gambit attack against Black's doubled
QP. An error jeopardising the Kt. Black develops his Queen to QR4(a5)
with check to fork Black's knight, and 5..QxKt is
unstoppable.
White Black
1. P-K4 P-QB4
2. P-Q4!? PxP
3. Kt-KB3 P-K4
4. KtxP?? Q-R4 ch!