Chess

ON TUESDAY I described the victory of the German programmer, Stefan Meyer-Kahlen, and his creation Shredder in the Ninth World Computer Championship in Paderborn. This finished last Saturday, and after the prize-giving on Sunday morning the top five were pitted against five human grandmasters.

Games between computers and humans are quite different from those between the monsters themselves for at least two reasons. The first, which only affects the humans, is the disconcerting psychological problem of facing a totally impassive opponent rather than the people with extremely strong emotions (however well masked) that we grew up against. But we're all pretty used to playing machines nowadays, and in this case the presence of the often far from impassive computer operators does compensate somewhat.

The technical aspects of playing a machine are also different from a human opponent since we are still so much stronger strategically, though certainly no better and usually weaker in tactical melees. The human will therefore tend to initiate strategic action - or trick the machine into doing something wrong off its own bat; and we often get marked advantages but then succumb in the end to their tactical prowess and remoreseless exploitation of any errors. Meanwhile, although the machine doesn't really "know" that it's playing a person, its programmers can still tweak its performance in various ways - and not just the opening book; for instance whereas it should only enter complications against computer opposition with caution, it would normally be correct to complicate against a person.

The tension between the strategic and tactical aspects of the game tends to lead to a far higher proportion of draws in man/machine than machine/machine contests. And indeed, whereas just 23 of the 106 world championship games were drawn, three of the five played on Sunday - Lutz v Shredder, CilkChess v Alterman and Junior v van Wely - ended peacefully. In the other two Rafael Vaganian slowly outplayed Ferret in his favourite French Defence and won in 77 moves. Far more publishable though, is poor Ivan Sokolov's loss to Fritz.

Ivan seemed to be doing things right by getting the queens off early, but in the human's greatest nightmare he got hit by an overwhelming tactical shot.

After 14.Bh6! if 14...gxh6 15.Nf6+ Kf8 16.Rd8+ Kg7 17.Nh5+ Kg6 18.Rxh8 etc; or 14...Rg8 15.Bxg7! Rxg7 16.Nf6+ Kf8 17.Rd8 mate. And of course Black can't castle since the king's moved.

White: Fritz

Black: Ivan Sokolov

Paderborn 1999

Ruy Lopez Berlin Variation

Jspeelman@compuserve.com