Kaissa

Kaissa (Russian: Каисса ) was a Soviet chess program , in 1974 the first World Computer Chess Championship won. It was named after the fictional chess goddess Caissa . The Elo rating Kaissas was about the 1600th

Kaissa was developed by Vladimir Arlasarow, Alexander Bitman , Georgi Adelson-Welski , Alexander Schiwotowski and Anatoli Uskow and later improved by Mikhail Donskoi. It was developed at the Institute for Theoretical and Experimental Physics and the Institute for Systems Science in Moscow. In 1974 the program contained 384 kilobytes of assembler code.

It contained mechanisms like a predecessor of the zero-move search , through which Kaissa could identify threats. It could understand positional analogies and had a tree search with alpha-beta search mechanisms .

In 1972, the program played two correspondence games (1 draw , 1 loss) against the readers of the Komsomolskaya Pravda newspaper and thereby gained notoriety in the Soviet Union.

Kaissa was world computer chess champion from 1974 to 1977 . It won the first four-round World Championship in Stockholm in August 1974 , in which 13 programs took part. It had 10,000 moves in the opening book and ran on a mainframe computer from ICL . The ICL 4/70 had a 64-bit processor, 24,000 bytes of RAM and was able to process 900,000 commands per second, which was sufficient for around 200 positions per second. The development team was banned from buying and using an IBM computer, although it might have been more powerful. At the World Championships, the program took part via an ICL in Moscow and a telephone connection, as the Stockholm ICL computers could not have run the program due to the lack of a specially developed operating system .

The Soviet government stopped the further development of Kaissas, because they considered it a waste of time. Nevertheless, the program took part in other world championships.

In 1977 it finished second to third in the second world championship, while CHESS won 4.6 . At the third World Cup in 1980, Kaissa finished sixth to eleventh with a performance of 1634 Elo, while Belle and Chaos shared victory.

Duchess - Kaissa
Toronto, 1977

	a	b	c	d	e	f	G	H
8th									8th
7th									7th
6th									6th
5									5
4th									4th
3									3
2									2
1									1
	a	b	c	d	e	f	G	H

Black to move.

Kaissa played one of the most remarkable moves in computer chess history at the 2nd World Computer Chess Championship in Toronto in 1977. On move 34, the program pulled Re7 – e8, which at first glance was completely incomprehensible, which lost the rook without replacement. At first the audience believed there was a program error , but it turned out that after the obvious 34 ... Kg8 – g7 a mandatory checkmate combination was possible: 35. Qa8 – f8 + Kg7xf8 36. Be3 – h6 + Bf6 – g7 37. Rc1 –C8 + and mate. So the program played the move that delayed losing the game for as long as possible. Against a human player, it would have made more sense to let the move Kg7 arrive, because the opponent might not have seen the checkmate, while after losing the rook a position without any chance arises.

source

• Archived Geocities page ( Memento dated November 16, 2005 in the Internet Archive )

Footnotes

1. ↑ Kaissas chess games on chessgames.com

Web links

• Replayable chess games by Kaissa on chessgames.com (English)