The on-again, off-again semifinal matches in the current World Championship series are on again - this time in London. The matches, both of which were apparently forfeited last summer when the Soviet Union refused to accept the original sites, have been rescheduled to run concurrently, beginning Nov. 19. As before, it will be perennial challenger Viktor Korchnoi vs. young Soviet star Gari Kasparov in one contest, and former world titlist Vassily Smyslov of the Soviet Union vs. Hungarian grandmaster Zoltan Ribli in the other, with the winners meeting later for the right to play a title match against World Champion Anatoly Karpov.
Korchnoi, who will be trying for his third crack at Karpov's title, will likely meet an insurmountable obstacle in Kasparov. After Kasparov's impressive recent victory at Niksic, Yugoslavia, it is estimated that his rating will approximate that of Karpov.
During the Niksic tournament a blitz championship was arranged (each player having five minutes on his clock to complete all his moves), with a $1,000 first prize. Korchnoi, who was a visitor at the tournament, was allowed to participate in the double round-robin blitz event. Kasparov won both of their head-to-head games and dominated the tournament as a whole with 13 1/2 points. Korchnoi was next with 10 1/2, followed by Tal, 9 1/2; Ljubojevic, 8 1/2; Spassky and Timman, 7; Sax, 6; Larsen, 5 1/2; and Ivanovic, 3 1/2.
Korchnoi's prediction about the tournament was correct. He said he and Kasparov would capture the top two places.
One of the Kasparov-Korchnoi games follows. Most of us would be proud to play such a game under tournament conditions and time control; that young Kasparov could produce it in less than five minutes of cerebration is indeed impressive.
Nimzo-Indian Defense Kasparov Korchnoi 1. P-Q4 N-KB3 2. P-QB4 P-K3 3 N-QB3 (a) B-N5 4. P-K3 O-O 5. P-QR3 BxN ch 6. PxB P-Q3 7. B-Q3 P-K4 8. P-K4 P-B4 9. N-K2 N-B3 10. O-O B-N5 (b) 11. P-B3 B-R4 12. P-Q5 (c) N-R4 13. P-N4 B-N3 14. P-KR4 NxNP (d) 15. PxN QxP 16. R-B2 QxP ch 17. R-N2 Q-Q2 18. N-N3 P-B3 19. QR-R2 P-N4 20. PxP P-B5 21. B-K2 QxP 22. B-N4 N-N2 23. B-K6 ch K-R1 24. R(R)-N2 Q-B4 ch 25. K-R1 Q-B2 26. N-B5 N-B4 27. RxB NxB (e) 28. R-KR2 K-N1 29. RxRP (f) KxR 30. Q-R5 ch K-N1 31. PxN R(B)-K1 32. B-R6 R-K2 33. NxR ch QxN 34. RxP ch Black resigns
A. In tournament games Kasparov usually plays 3. N-KB3 to avoid the Nimzo-Indian Defense and to opt for the Queen's Indian, of which he is the acknowledged master.
B. A dubious idea, since it results in the Bishop's being ''off side,'' as opposed to its normal development on the Queenside in this type of opening.No doubt Korchnoi hoped his opponent would overextend.
C. Even under blitz conditions Kasparov follows the sound principle of securing the center before attacking on the Kingside.
D. Korchnoi, aware that passive defense offers few prospects, sacrifices a piece for three pawns. Normally this is a fair exchange; here this strategy is doomed to failure, since White's good development, open files, and extra piece result in an irresistible attack.
E. Naturally if 27. . . . PxR, 28.R-R2, mate.
F. The coup de gracem that effectively puts an end to Black's resistance.