Chess Board
[ECO code C42]
PETROFF'S DEFENCE - Marshall Attack
White's Bishop on Q3(d3) removes Black's KP on K4(e4), and now supports his doubled QP.
Black's Q2(d7) Knight moves to KB3(f6) forking White's Q5P and bishop. Slight advantage to White.
    White  Black     7.	0-0    B-KKt5
 1. P-K4   P-K4	     8.	P-B4   0-0
 2. Kt-KB3 Kt-KB3    9.	PxP    P-KB4
 3. KtxP   P-Q3	    10.	Kt-B3  Kt-Q2
 4. Kt-KB3 KtxP	    11.	P-KR3  B-R4
 5. P-Q4   P-Q4	    12.	KtxKt  PxKt
 6. B-Q3   B-Q3	    13.	BxP    Kt-B3
Example ends: Undo or Jump or Clear