Chess Board
[ECO code C80]
RUY LOPEZ - Open Morphy Defence
(The) Side Variation

Black's king's-side knight captured White's KP.
White's QB loses more than a tempo taking the QB6(c6) knight here. It gives Black a Berlin Rosenthal with a move in hand, and advantage. W-Alt.
    White  Black	White  Black
 1. P-K4   P-K4	     6.	BxKt??
 2. Kt-KB3 Kt-QB3
 3. B-Kt5  P-QR3
 4. B-R4   Kt-B3
 5. 0-0    KtxP

Example ends: Undo or Jump or Clear