Game 25. Nimzowitsch—Dr. Michel, Semmering, 1926. Illustrates the idea of collective mobility, and touches also on the problem of prophylactic.

1. 4…e6 A new idea. Black avoids developing the Kt at QB3, since it might be pinned by B-QKt5.
2. 6…a6 B-Q3 was much better here than the text move, firstly with regard to his development, and secondly because White threatens to make strong use of the diagonal QKt2 to KKt7, taking advantage of it to support his outpost at K5. A prophylactic measure was urgently needed. For instance 6. ....B-Q3!; 7. KtxKt, BxKt; 8. BxB ch, QxB; 9. BxKt, PxB, and the doubled pawn has both its dark and its bright side. (See II. ii.) Further we consider 6. ....B-K2 also better than the text move (P-QR3).
3. 9…f6 An admission of weakness in the long diagonal. There came under consideration also 9. ....B-Q3, e.g., 9. ....B-Q3; 10. Q-Kt4, Q-B2, followed by O-O-O.
4. 10…dxc4 The threat was 11. PxP, PxP; 12. Q-R5 ch, followed by QxQP.
5. 14.Qh3 The best place for the Q and one difficult to find. P-K4 would now only surrender the point Q4 to White. For instance 14. ....P-K4; 15. Q-Kt3 (threatening BxP), B-Kt2; 16. P-K4, followed by P-Q3 and Kt-QB3-Q5 with advantage in position for White.
6. 16.a4 White plans the configuration PK4, PKB4, etc., which would leave his QP backward. As he thus sacrifices the effective power of his QP, he must necessarily first paralyse the three Black Q side pawns. Hence the text move.
7. 19.g4 A ‘pawn roller’ which can hardly be rendered innocuous.
8. 19…f5 If Black does nothing, White has the choice between a direct attack on the one hand and play against the QBP on the other. The latter could be carried out in some such way as say 19. ....QR-K1; 20. Q-K3 and then P-R5 and B-R3, finally driving away the defending BQ3 by P-K5. After the text move a mating attack wins the game straight off.
9. 20…exf5 Or KtPxP; 20. K-B2, etc.
10. 21.e5 The following variation may be dedicated to those who love combinative complications. 21. Kt-Q5 (instead of P-K5), QxP; 22. QR-K1, QxQBP; 23. Kt-K7 ch, BxKt; 24. RxB, R-B2; 25. RxR, QxR; 26. Q-QB3, K-B1!; and Black, it would appear, has a sufficient defence.
11. 22…Bxd5 If on his 21st move Black had played his B back to QKt1, he would now have been able to answer the entry of the Kt by Q-K3; but this, too, would have availed nothing. For example: 21. ....B-Kt1; 22. Kt-Q5, Q-K3; 23. Kt-B6 ch, RxKt; 24. PxR, Q-K5 (his one chance); 25. P-B7 ch, and White wins by 25. ....KxP; 26. QxRP ch; K-B1; 27. Q-Kt7 ch, K-K1; 28. R-K1, etc.
12. 24.e6 For if QxQP, Q-R6 forces mate, or the loss of a R, and if 24. ....Q-K2, the fatal Q shows herself at her QB3 and there is no answer.