1…c5With this move Black tries to avoid well-trodden paths of tournament practice. White can, at will, lead into a peaceful Queen's Gambit by 2 P—K 3 or into a Sicilian Defence by P—K 4. It is more usual, however, to play P—Q 5, which blocks up the Black centre to some extent. If 2 P x P, Black regains his pawn after P—K 3 without any disadvantage.
2.d5Coupled with 4 P—K 4, this move is of doubtful value, as Black gains command of White's Q 4. It is advisable to keep the Q B P back, thus retaining the option of driving off a hostile piece from Q 4 by P—Q B 3. Moreover, the White K B is hemmed in by the pawn at Q B 4.
6…Ne7The development of the K Kt is not desirable at B 3, where it would block the long diagonal. From K 2, however, it commands K B 4, where it can take up a strong position after the exchange of pawns in the centre, or else it can support the advance of the K B P.
9.f4This move weakens the King's position, and would be justified only if there was a possibility of opening the file for the Rook by P—B 5. But Black has too strong a hold on his K B 4. The text move aims at preventing the exchange of White's K B through Black's Kt—K 4. It would have been better to withdraw the B to B 2.
10…h5Now White cannot enforce P—B 5, as Black can attack the Knight by P—R 5. White cannot prevent this while P—K R 4, as the Black Knight would take up a commanding position at Kt 5. Black's game is superior. He can concentrate all his minor pieces on the King's wing, while White's Q B is ineffective on account of the ill-considered advance of the K B P.
13.Bxe4White has to capture while the B, in order to exchange the Black Knight if it should play to B 4. After 13 Kt x Kt, B—Q 5 ch; 14 K—R 1, Kt—B 4; White's Knight would not be able to move from K 4 on account of the threat: Kt—Kt 6 ch. Sooner or later, Black would get a deciding advantage by enforcing the exchange of White's Knight.
15.Bxf5White is helpless against the two powerful Bishops.
16…Kf8Black forfeits his chance of castling, not a great loss under the circumstances. In any case his K R is needed on the Rook's file, and Black would only have castled on the Queen's side if at all.
17.Qf3Here P—K R 3 was essential in order to prevent the further advance of the K R P. The weakness at Kt 3 would not have been so serious in the absence of a Black Knight. Now Black forces the advance of White's K Kt P, and the Bishops become immediately effective.
18.g3not P—K Kt 4 on account of Q—R 5.
20.Qf1If Q—Q 3, Black plays Q—B 4 and White cannot exchange Queens because of B—B 6 mate.
20…Qf5threatening Q—B 7.
22…Bf6Black must not exchange his valuable Bishop.
24.Bf2There is no answer to Black's threat of doubling the Rooks on the K file. If White plays Q—B 2, Black's Queen effects an entry at Q 6, after which he would double his Rooks, and White's Bishop cannot be defended. After the text move, Black forces the exchange of his two Rooks for the Queen. Generally speaking, this is no disadvantage, but in consequence of the exposed position of the White King, it means a speedy loss for White.
28.Re8In order to play R—K 3 if Black plays B x Kt.
32…Qxh2+for the pawn queens.
Edward Lasker, Chess Strategy (1921) · Public domain · source