Brave New Chess World (ACJ Extra)

Brave New Chess World

Christopher Chabris

Garry Kasparov is still the world chess champion, but only because his May 1997 six-game match in New York against IBM's Deep Blue supercomputer was not played for the title he has held since 1985. For the first time in his career, Kasparov lost a match, by the narrow margin of 3.5--2.5.

Kasparov seemed to start well against his silicon opponent, winning the first game in a style that gave every indication that he would repeat his 1996 victory over Deep Blue's predecessor. But the next day's contest, which will be known to chess fans as simply "Game 2" for years to come, shocked the announcers, the audience, even Deep Blue's developers, and most of all Kasparov himself. Playing the white pieces the computer rolled over Kasparov with a masterpiece of subtle strategy -- until its final move. Instead of exchanging the queens and winning an endgame, Deep Blue allowed Kasparov to force a draw by perpetual check. But at the very moment of opportunity, Kasparov resigned the game. Neither player had seen the crucial continuation, which involved a long sequence of moves, some of which were paradoxically "quiet," or non-forcing, and which was first pointed out by a fan watching the game on the Internet. When Kasparov was told of his error the next day, he stopped in stunned silence in the middle of a busy New York street. Deep Blue had, inadvertently of course, landed a devastating double psychological blow on the champion. To first be comprehensively beaten from the start of the game and then to surrender in a drawn position was a unique and disturbing experience for Kasparov. Already he had been playing as though he feared the machine's powers, but now he had reasons to doubt his own.

Addressing the audience after the next game, in which he pressed hard to win but could only draw, Kasparov showed that he had not put the events of Game 2 behind him. Asked whether he suspected human intervention in Deep Blue's thinking at the critical moments, he said, "It reminds me of the famous [illegal] goal which Maradona scored against England in 1986. He said it was the hand of God." The next two games were drawn in similar fashion: Kasparov held the advantage and all of the winning chances, but was unable to finish the job against the computer's iron resilience and meticulous defensive play. After the fifth game Kasparov lingered in the playing room making protests and demanding that "logs" of Deep Blue's thinking during the game be sealed by the arbiter so he could examine them after the match. He later received a prolonged standing ovation from the audience, but he was clearly unraveling with obsession over the mystery of Deep Blue's powerful moves. "I'm not afraid to admit that I'm afraid, and I'm not even afraid to say why I am afraid ... It makes decisions that still cannot be made by any computer." The normally confident and even cocky world champion was nowhere to be found in these remarks. But still nobody predicted what would happen next.

Sunday the 11th of May, the Mothers Day holiday in the United States, saw Kasparov's mother arrive almost 30 minutes late for the start of the decisive game. Usually she is present for every move of her son's important matches. By the time she got to the playing room the situation was already grim. Kasparov had played an extremely risky opening variation that allowed Deep Blue to sacrifice a piece for a vicious attack. From the look of horror on his face most analysts guessed that Kasparov had made a simple mental error, accidentally playing one move when he had prepared another, and his spokesman later confirmed this account. It seemed as though the pressure and frustration that had been building up over the nine-day match had caused him to finally snap, and in an instant he was drained of the will to fight. In record time -- only 19 moves and 65 minutes -- Deep Blue demonstrated a winning advantage against the world champion.

After resigning the game in disgust, Kasparov walked off stage with a look of incredulity and rushed to a press conference where he said he was "ashamed" of his performance, that Deep Blue "hasn't proven anything," and that he would "tear it to pieces" in the future. He repeated his oblique references to possible cheating by the IBM side; when the Game 2 "hand of God" log was provided to him after the match his spokesman said that it did not include the information they needed to reach a conclusion. But almost all independent observers, as well as the official appeals committee, agreed that the allegations were unfounded and that no cheating had occurred.

So what are the lessons of this latest "chess match of the century"? It is appropriate that this event, described as the ultimate battle between man and machine, may teach us as much about human psychology as about artificial intelligence. For the first time the greatest genius in chess history was matched move-for-move by an artificial device, one that derived most of its chess skill by calculating the consequences of 200 million future board positions every second. Human beings can handle about one position per second, so the entire population of Brazil could only keep up with the computer if everyone in Argentina joined the work too! Until now we have had no standard against which measure human potential, let alone a way to calculate how much raw computer power would be needed to match it. The answer, represented by Deep Blue, should make us appreciate even more the unique abilities of the brain.

But we also learned that human-style thinking is not the only way to produce intelligent behavior. Kasparov himself has credited Deep Blue with "a new kind of intelligence," and the ability to transmute "quantity" into "quality." He understands from personal experience that arguing over how intelligent behavior is produced -- does it require intuition, judgment, creativity, or other elusive qualities, as opposed to mere "brute force" computation -- is irrelevant. Chess masters who had never seen or heard of games two and six would guess that a grandmaster played white and a computer played black in each case, not the other way around.

With the arrival of Deep Blue at the highest level the ancient game of chess is entering an exciting new era. The game is more popular than ever, especially among young people, and the worldwide media coverage of the match reached hundreds of millions. Kasparov threw the doors wide open to a brave new chess world at the post-match press conference: "Deep Blue must now enter competitive chess ... play in the candidates tournament, play a world championship match, under proper conditions and the scrutiny that every chess player has to go through." Allowing a computer to play for the world championship title has no precedent in backgammon or checkers, two games in which other computers have equaled Deep Blue's achievements in chess, and whether this will actually happen is a big question. But only politics, prejudice, or IBM's own reluctance to trade scientific research for sporting achievement can keep Deep Blue out of international competition. Its performance in this match shows that it is one of the greatest chess players of all time.

Christopher Chabris was Editor in Chief of American Chess Journal. A slightly different version of this article appeared originally in Portuguese in Veja magazine, 21 May 1997.