Chess Board
[ECO code C46]
THREE KNIGHTS OPENING
White's rear doubled Queen's Pawn moves on from Q3(d3) to Q4(d4) attacking Black's KP.
Black's King's Pawn removes White's rear QP and attacks the pinned QBP. Play often continues 10.Q-R4+ch..P-B3, 11.QPxP..KtPxP, 12.KtxP for equality.
    White  Black	White  Black
 1. P-K4   P-K4	     6.	P-B3   P-Q3
 2. Kt-KB3 Kt-QB3    7.	P-Q3   KtxKt
 3. Kt-QB3 B-Kt5     8.	PxKt   Kt-K2
 4. Kt-Q5  B-R4	     9.	P-Q4   PxP
 5. B-B4   Kt-B3
Example ends: Undo or Jump or Clear