Chess Board
[ECO code C23]
BISHOP'S OPG. TRANSPOSITION
CLASSICAL VAR. to PHILIDOR COUNTER-ATTACK
White's rare queen to K2(e2) for a later P-KB4 gambit also threatened 4.BxBP+ch, 5.Q-B4+ch, 6.QxB.
Black transposes into a Philidor Counter-Attack line by posting his QBPawn on QB3(c6) to ensure White's threat is met by a defended 5..P-Q4. B-Alt.
    White  Black    Transp.White Black
 1. P-K4   P-K4		  (1.)
 2. B-B4   B-B4	    (2.	B-B4   P-QB3)
 3. Q-K2   P-QB3!   (3.	Q-K2   B-B4!)
Continue: Transpose or Undo or Jump or Clear