Chess Board
[ECO code A13]
TRANSPOSITION
RETI'S OPG. to QUEEN'S PAWN SIDE-DEFENCE
Black's KP push resumed control of his Q4(d5) for 3..P-Q4 and freed his KB for a 3.Kt-QB3..B-QKt5 pin.
White effectively transposes, advancing his QPawn to occupy the centre for what usually becomes a Catalan Opening or a Queen's Indian Def.. W-Alt.
    White  Black    Transp.White Black
 1. Kt-KB3 Kt-KB3   (1.	P-Q4   Kt-KB3)
 2. P-B4   P-K3	    (2.	P-QB4  P-K3  )
 3. P-Q4	    (3.	Kt-KB3 	     )
Continue: Transpose or Undo or Jump or Clear