DeepThought : The computer chess Champion By : Anonymous Rebel The artificial intelligence pioneer, Herbert Simon, predict- ed that by 1967 a computer would be able to beat any human in chess. However, he was quite far off. In 1989, the human mind can still defeat even the greatest of computer chess machines. Simon wasn't as far off as the critics of the Fifties, who claimed that a computer could never master chess. A computer called Deep Thought now plays at the level of a human grandmas- ter, which means that only about 200 people in the world can defeat him. Deep Thought has not exactly been ranked as a grandmaster as of yet, because according to Thomas Anantharaman, one of the creators of Deep Thought, "You can't claim to be a grandmaster unless you are a human being." However, this hasn't upset his fellow creators or him. So far, they have won $10,000 from The Fredkin Fund, for winning 25 straight games in world competition. ($100,000 is waiting for the first electronic world champion.) Deep Thought follows the tradition of its computer predeces- sors, by considering every possible move. Good human players usually examine only a few moves, and rely on pattern recognition and experience to succeed. This type of evaluation proves ex- tremely difficult to program into a computer, although the former computer chess champion, Hitech, was designed to recognized certain programs. However, ruling out certain moves, without fully examining all the possibilities will eventually lead to an error in the computer's part. Although a computer lacks the ability of insight, they make it up in their ability to number crunch. For example, in a typical situation, a chess player has 38 moves to consider. To check all the responses would mean examining 1444 different positions. To look one step ahead would mean checking over 2 million positions. The secret of the computer's success, obviously, is its incredible speed. Even a little toy chess computer is fast enough to beat most people. The big time computers like Deep Thought is even faster. In fact, the ultrafast electronics are the source of power for all Fredkin prize hopefuls. Deep Thought is simply the fastest around. Deep thought is designed to examine five moves ahead. Since this is far from seeing the end of a game, the machine must not only check what positions it could end up in, but must evaluate them as well. Typical considerations include the value of what pieces will be captured, and whether the King will be put in check. Deep Thought also checks its position on the board, and the number of empty squares from which the King could be at- tacked, and some 80 other items. Deep Thought gives numerical values to all of the considerations, and uses the highest ranked move. All of the world-class chess computers uses certain varia- tions on this approach. The reason for Deep Thought's success is that it doesn't always hold itself to a few moves. If one move seems particularly good, it searches down that path for up to 15 moves. This strategy is called singular extension. If Deep Thought registers an equally dangerous threat, it also searches further, it works in the same manner, but this time its called Threat Extension. If this feature comes into play, the results are usually deadly for the opponent. Deep Thought didn't used an experienced chess player to assign relative values to its 80 considerations, like other chess computers. Hitech had used Hans Berliner, a computer scientist and a former world-class champion. "The fascination," Ananthara- man says, "was writing a program that can do something I can't do." Instead, the computer watched games played between human grandmasters. One of the programmers "tuned" Deep Thought's evaluation equation until it started choosing Grandmaster style moves. First approximations were made in deciding the order. Deep thought would use this hierarchy and replay the grandmaster games. At first, Deep Thought played horribly. But after each game, the program would change the rank slightly until Deep Thought was playing like a true grandmaster. After 800 games, Deep Thought was playing like a true master. Anantharaman was truly surprised that the "tuning" worked as well as it did. After evaluating the process, he decided that this process is a better technique even if you have the expert knowledge. The approach could also be used in other fields where human experts aren't available. The trouble is that not many problems are as well defined as that of chess. Some day the thinking process would be useful to the military, but that is far off. "Computer chess will give you an idea how to approach a problem," says Anantharaman, "but it won't solve the problem completely. I can't think of a single real-world problem that has been solved by artificial intelligence." Bibliography "Pawn to King Four." Tom Waters. Discover Magazine, May 1989. Volume 10, Number 5 X-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-X Another file downloaded from: NIRVANAnet(tm) & the Temple of the Screaming Electron Jeff Hunter 510-935-5845 Rat Head Ratsnatcher 510-524-3649 Burn This Flag Zardoz 408-363-9766 realitycheck Poindexter Fortran 415-567-7043 Lies Unlimited Mick Freen 415-583-4102 Specializing in conversations, obscure information, high explosives, arcane knowledge, political extremism, diversive sexuality, insane speculation, and wild rumours. ALL-TEXT BBS SYSTEMS. Full access for first-time callers. We don't want to know who you are, where you live, or what your phone number is. We are not Big Brother. "Raw Data for Raw Nerves" X-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-X