Chess Board
[ECO code C42]
TRANSPOSITION
PETROFF DEF. (Russian 3Kts) to PHILIDOR DEF.
White developed his QKt to defend his KP in reply to the Black KKt development counter-attack.
Black here transposes into Philidor's Def. heading for the Jaenish Counter-Attack line by pushing his Queen's Pawn out to Q3(d6) in defence of his KP, rather than (best) deploying a 3..B-QKt5 pin. B-Alt.
   White  Black	    Transp.White Black
 1.P-K4   P-K4		  (1.)
 2.Kt-KB3 Kt-KB3    (2.	Kt-KB3 P-Q3  )
 3.Kt-B3  P-Q3	    (3.	Kt-B3  Kt-KB3)
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