Chess no. 411

PHILIDOR

Black 8 men II men

Specially contributed by H. Davison (Bradford). White to play and mate in two moves; solution next week.

Solution to no. 410 (Sammelius): Q - B 3, threat Q - B 5. 1 B - K 4; 2 Q - B 7. I R - K 4; 2 B- B 5. 1 . . . Kt - K 4; 2 R x B. Compare these mates with the three corresponding mates, after the try I Q- Q 3 (defeated by 1 . . .

R - K 5!), to see the point of this typically modern problem.

Especially in certain openings—of which the Sicilian is one—it is almost impossible to com- pete unless you know the latest theory. The following interesting game illustrates the point.

White, Contedini. Black, Grassi. Opening, Sicilian. (Milan 1968.)

1 P- K 4 p-.QB4 2 Kt-KB3 Kt-QB3 3 Kt-B3 P-KKt3 4 P-Q 4 P xP

5 Kt x P B - Kt 2 6 B - K 3 Kt - B 3 7 B-QB 4 Q-R 4 8P-B3?

8 0 - 0 is correct. In the variations where Black has not played P - Q 3, White has not got time for B - Q B 4 and P - B 3; if he wants to play the P - B 3, Q - Q 2, 0 - 0 - 0 line he must delay B - Q B 4.

s . . . Q - Kt 5! 9 B - Kt 3 Kt x K P!

10 Kt x Kt . . . 10 P X Kr, B x Kt; 11 B X B, Q X B; and Black is a sound pawn ahead.

10 . . . BxKtch 11 P X B Q x P ch 12 K-K 2 QPXKt Now 13 P X Kr??. B - Kt 5 ch.

13 B - Q 4? P- K 4! Black has outplayed White and established a winning position with two extra pawns—but it is all knosvn. recently published analysis; White had just not seen it.

14 B-K 3 P-QR4 15 R-KB1 P-R 5 16 BxPch K x B 17 PXKtch K- Kt 2

18 R- B 3 . . . 18 Q- Q 2 would also lose, e.g. 18 . . . Q - B 5 ch: 19 Q - Q 3. B - Kt 5 ch; 20 K - B 2, Q X Q; 21 P x Q, Q R - Q 1 and Black is winning.

18 . . . B-Kt 5 19 K-B 2 KR-B1

19 . . B X R?; 20 Q Q 7 ch, K - B 3 (forced); 21 Q - Q 6 eh and draws.

20 R - Kt 1 P - Kt 4 21 Q - Q 6 QxPch 22 K- Kt 3 QxK P 23 Q-K7ch K-Kul

24 RxRch R xR 25 B- R6 ...

Black is MTh, unable to defend himself directly against the threat, of 26 Q - Kt 7 mate (25 ... R - B 271; 26 Q - K 8 ch); however . . .

25 . . . R-B6ch! 26 P x R QxPch 27 K - R 4 Q-R 6 ch 28 .K - Kt 5 Q-R 4 eh 29 K-B 6 Q-B 4 mate.