Chess Board
[ECO code D31]
QUEEN'S GAMBIT - Petrosian Var.
Exchange Variation
White develops his King's Knight to KB3(f3) but may not castle, needing his KR to defend his K-side.
Black castles, bringing his king's rook into play with a sound position, and equality.
    White  Black	White  Black
 1. P-Q4   P-Q4	     6.	P-K3   B-KB4
 2. P-QB4  P-K3	     7.	P-KKt4 B-K3
 3. Kt-QB3 B-K2	     8.	P-KR3  Kt-B3
 4. PxP	   PxP	     9.	Kt-B3  0-0
 5. B-KB4  P-B3
Example ends: Undo or Jump or Clear