Queen's Gambit Accepted, Mannheim Variation

MARK TAIMANOV vs. LEV POLUGAEVSKY
USSR Championship, 1960

1. d4, d5
2. c4, exd4
3. Nf3, Nf6
4. Qa4+ ....

The Mannheim Variation.

4. .... Nbd7
5. Nc3, e6
6. e4, c5
7. d5, exd5
8. e5, d4
9. Bxc4, dxc3
10. exf6, Qxf6
11. Bg5, Qc6
12. 0-0-0, cxb2+

If 12....Qxa4, then 13. Rhe1+ Be7, 14. Rxe7+ Kf8, (if 14....Kd8, then 15. Rxd7+ Ke8, 16. Rd8 mate.) 15. Rxf7+ with a mating attack.

13. Kxb2, Be7
14. Rhe1, f6
15. Bb5, Qb6
16. Kc1 ....

Removing the King to safety in case Black moves pawn to a6.

16. .... fxg5
17. Bxd7, Kf8
18. Rxe7!! ....

White sacrifices the Rook in order to expose the King.

18. .... Kxe7
19. Qe4+, Kd8
20. Bf5+, Kc7
21. Qe5+, Kc6
22. Rd6+, Kb5
23. Qb2+, Resigns

Black can only escape mate at the cost of materials, including his Queen.