Chess Board
[ECO code A47]
QUEEN'S INDIAN DEF. - Marienbad System
Berg Variation
White develops his Queen to QR4(a4) to defend his QBP, and pins Black's QP to its king.
Black castles, breaking the pin, and has equality.
    White  Black	White  Black
 1. P-Q4   Kt-KB3    7.	0-0    B-Kt2
 2. Kt-KB3 P-QKt3    8.	Kt-B3  Kt-B3
 3. P-KKt3 B-Kt2     9.	Q-Q1   Kt-QR4
 4. B-Kt2  P-B4	    10.	Kt-Q2  BxB
 5. P-B4   PxP	    11.	KxB    Q-B1
 6. QxP    P-Kt3    12.	Q-R4   0-0
Example ends: Undo or Jump or Clear