Chess Board
[ECO code B23]
SICILIAN TRANSPOSITION
CLOSE VAR. to ORTHODOX / 4KTS VAR.
Black's QBP removed White's QP to stop P-K5.
White's K2(e2) Knight exchanges, removing the doubled QP on Q4(d4) to threaten KtxKt, P-K5, and completes a transposition into the Orthodox line. 
    White  Black    Transp.White Black
 1. P-K4   P-QB4	  (1.)
 2. Kt-QB3 Kt-QB3   (2.	Kt-KB3 Kt-QB3)
 3. KKt-K2 Kt-B3    (3.	P-Q4   PxP   )
 4. P-Q4   PxP	    (4.	KtxP   Kt-B3 )
 5. KtxP	    (5.	Kt-QB3	     )
Continue: Transpose or Undo or Jump or Clear