Chess Board
[ECO code E01]
TRANSPOSITION
QUEEN'S CATALAN OPG. to NIMZO-INDIAN DEF.
White developed his QKt to form a combined attack against Black's QP, making 4..PxP fairly inevitable.
Black transposes into the Steiner line of the Nimzo-Indian by developing his King's Bishop to QKt5(b4) to pin White's QKt and enable ..0-0. B-Alt.
    White  Black    Transp.White Black
 1. P-Q4   Kt-KB3	  (1.)
 2. P-QB4  P-K3		  (2.)
 3. P-KKt3 P-Q4     (3. Kt-QB3 B-Kt5)
 4. Kt-QB3 B-Kt5    (4. P-KKt3 P-Q4 )
Continue: Transpose or Undo or Jump or Clear