Chess Board
[ECO code B04]
ALEKHINE'S DEFENCE
Exchange Var. #2 ("5..BPxP")
White's KP removed Black's Q3(d6) pawn to prevent Black disruption of White's centre.
Black exchanges on Q3(d6) but removes White's doubled queen's pawn with his QBPawn. 
    White  Black	White  Black
 1. P-K4   Kt-KB3    6.	PxP    BPxP
 2. P-K5   Kt-Q4
 3. P-Q4   P-Q3
 4. Kt-KB3 P-Kt3
 5. P-QB4  Kt-Kt3  Alt. 5W-6B,4WB route
Example ends: Undo or Jump or Clear