Chess Board
[ECO code E12]
QUEEN'S INDIAN DEFENCE
Petrosian System
Black develope his king's bishop to QB4(c5), set a joint attack on White's KBP and enabled castling.
White's Q2(d2) Knight returns to KB3(f3), prevents 10..QxBP++mate and the game has equality.
    White  Black	White  Black
 1. P-Q4   Kt-KB3    6.	KtxKt  BxKt
 2. P-QB4  P-K3	     7.	Kt-Q2!? B-Kt2
 3. Kt-KB3 P-QKt3    8.	P-K4   Q-B3
 4. P-QR3  B-Kt2     9.	P-Q5   B-B4
 5. Kt-B3  Kt-K5    10.	Kt-B3
Example ends: Undo or Jump or Clear