Chess Board
[ECO code D00]
QUEEN'S PAWN GAME
The Stonewall Attack
Black's QKt to QB3(c6) supported ..P-K4 without blocking his QB in.
White plans Kt-KB3, and advances his KBPawn to KB4(f4) first (completing a stonewall formation) to avoid it being blocked, and stops 5..P-K4. W-Alt.
    White  Black	White  Black
 1. P-Q4   P-Q4	     5.	P-KB4
 2. P-K3   Kt-KB3
 3. B-Q3   P-B4
 4. P-QB3  Kt-B3
Example ends: Undo or Jump or Clear