Chess Board
[ECO code C30]
KING'S GAMBIT DECLINED
Petrov's Defence
White's KKt developed to KB3(f3), supporting his KP and preventing 4..Q-R5+ch.
Black's Knight on K5(e4) moves (best) to Kt4(g5) and invites a 5.KtxKt..QxKt exchange for faster development. White still gains a small advantage.
	White	Black
 1.	P-K4	P-K4
 2.	P-KB4	Kt-KB3
 3.	PxP	KtxP
 4.	Kt-KB3	Kt-Kt4
Example ends: Undo or Jump or Clear