Chess Board
[ECO code C67]
RUY LOPEZ - Open Berlin Def.
Side Variation
White's Q4(d4) Knight captures the Black bishop on QB6(c6), threatens 13.KtxP and invites capture.
Black's QKt2(b7) Pawn exchanges Kt-for-B on QB3(c6) but White has a pawn value advantage.
    White  Black	White  Black
 1. P-K4   P-K4	     7.	KtxP   Q-B3
 2. Kt-KB3 Kt-QB3    8.	P-KB3  B-QB4
 3. B-Kt5  Kt-B3     9.	B-K3   B-Q2
 4. 0-0	   KtxP	    10.	BxKt   BxB
 5. P-Q4   PxP?!    11.	PxKt   PxP
 6. R-K1   P-Q4	    12.	KtxB   PxB
Example ends: Undo or Jump or Clear