PxPRP xP

Q3 20 B-QN4 Q x B 21 QxN+ Evans. 21 B xN P-N5 22 R-QB3 with the dual threats 23 BxR and 23 R-KR3+ Tal. The position in diagram 158 is critical for this line. There are two continuations a) 20 N-B3 B-N2 21 R-N6 N-B5 22 B xN P xB 23 R-Ql Q-K2 24 R-K6 Q-B4+ 25 K-Bl R B1-Q1 26RxR+RxR 27Q-R4Q-B8 + 28 K-B2 B-KB1 29 P-QN4 B-K5 30 R-K8 (Better 30 Q-JST5) 30 . B-B3 31 Q xB Q xQ 32RxRQ-B3 33 R-B8 Q-K2 34 K-Bl K-R2 35 N-Q4 B-N2 36 N-N5 B-K4 37 P-QR3Q-Q2 38 R-QR8 P-B6 39 PxP BxP 40 K-N2 Q-N2+ 41 KxB Q-K4+...

Br

As in several similar positions in the classical system Black aims to exchange his inactive black-squared bishop. 10 P-QN4 P-QR4 The alternative is 10 . . . N-Kl and now a) 11 N-N3 B xB 12QxBand al) not 12 P-QB3 13 PxP PxP 14 P-QR4 B-K3 15 P-N5 P-KB4 16 P-B4 P-QR3 (Velimirovic suggests 16. . . P-Q4 with an unclear position) 17 BP x P RP x P 18RPxP RxR 19 Q xR QP xP 20 Q-R5 N-Q3 21 R-Ql PxKP 22 QxQ RxQ 23 N-B5 B-Bl 24 P-N6 with a winning position, Mecking-Naran-ja, Palma 1970. a2) but 12 P-KB4...

BP xPPQR

A) 10 N-N3 N-Kl 11 B-Q3 N-B4 12 B-QB2 P-B4 13 B-B2 P-B5 (13 B-R3J ) 14 N-Bl P-QR4 (14 Q-N4 15 R-KN1 Q-K2q ) 15 P-QR3 B-Q2 16 N-Q2 P-QN4 17 Q-K2 R-Nl 18 0-0 P-N4 (18 . . . P-R5-) 19 P-QR4 Petrosian-Penrose, Palma 1969. b) 10 P-KN4 P-KR4 11 P-KR3 and now bl) 11 N-R2 12 P xP Q-R5 + 13 B-B2 Q x P R4 14 N-N3 Q-N4 b2) 11 N-N3 12 B-N5 Q-Kl 13 B-R4 B-Q2 14 P-QN3 Bobotsov-Ong Yok Hwa, Zwolle 1966. 10 P-KN4 An idea of Lilienthal's is 10 N-N3, but it appears unconvincing after 10 P-QN4 11 P-KR4 P-N5. 10...

RNl

D421 12 P-QR4 13 B-Bl Q-B2 14P-QR4 after which White is worse. Correct, of course, was 14 P-N3 intending P-R3 and P-QN4. P-QR4 in such situations is only good for White (cf. D422) if the exchange BP xQP answered by BP x QP has occurred. In that case P-QR4 contributes towards the control of the Q-side light squares (b5 c4) which White can occupy with pieces. If White plays P-QR4 before this exchange has occurred he merely blockades his own army, since the squares b5 and c4 are not yet available...

Knk Qr

Osnos-Vogt, Zinnowitz 1971, went 13Q-Q2P-B5 14BxNPxB 15 Q-Q3 N-B3 Not 15 BxP 16 QxP 16 0-0-0 Q xBP 17 P-N5P-K5 18Q-Q2N-R4 19NxKP Q-R5 20 R R1-B1 If 20 N xQBP P-B6 21 N-B3 N-N6 22 R-R2 BxN 23 PxB QxBP F Uhl-mann 20 P-B6 21 N-Nl N-N6 with much the better prospects for Black. After 1 P-Q4 N-KB3 2 P-QB4 P-KN3 3 N-QB3 B-N2 4 N-B3 0-0 5 P-K4 P-Q3 6 B-K3 263 Larsen used this move during his run of tournament victories in 1967, though it was known at least as far back as 1931. This seems best...