Chess Board
[ECO code C86]
RUY LOPEZ TRANSPOSITION
WORRALL ATTACK to HOWELL ATTACK
White's QP removes Black's KP on K5(e5). These three single-moves are the basis of the Open Def.
Black develops his Queen's Bishop to K3(e6) transposing into a Howell Attack variation. 
    White  Black	White  Black
 1. P-K4   P-K4      6.	Q-K2   P-QKt4
 2. Kt-KB3 Kt-QB3    7.	B-Kt3  0-0
 3. B-Kt5  P-QR3     8.	P-B3   P-Q4!
 4. B-R4   Kt-B3     9.	P-Q4   KtxKP
 5. 0-0    B-K2	    10. PxP    B-K3
Continue: Transpose or Undo or Jump or Clear