> Deep Blue Defeats Kasparov_

On May 11, 1997, in a room at the Equitable Center in midtown Manhattan, the reigning world chess champion Garry Kasparov — widely considered the greatest chess player in history — resigned his sixth and final game against Deep Blue, an IBM supercomputer. He had lost the match 3.5 to 2.5. It was the first time a reigning world champion had been defeated by a machine in a formal match under standard time controls, and it sent shockwaves through the world. Newsweek's cover read "The Brain's Last Stand." Kasparov, visibly shaken, stormed away from the table and later accused IBM of cheating.

The match had been a rematch. In February 1996, Kasparov had played an earlier version of Deep Blue and won 4-2, though the machine had taken one game — the first time a computer had beaten a world champion in any game under standard conditions. IBM's team, led by Chung-Jen Tan and programmer Murray Campbell, spent the intervening year dramatically upgrading the system. The 1997 Deep Blue was a massively parallel machine containing 480 custom chess chips, capable of evaluating approximately 200 million positions per second. Its evaluation function had been tuned with the help of grandmaster Joel Benjamin, and its opening book drew on a vast database of historical grandmaster games.

The pivotal moment came in Game 2. Deep Blue played a move — 36...Be4 — that stunned the commentators and Kasparov himself. It appeared to show genuine strategic understanding, sacrificing short-term advantage for long-term positional gain. Kasparov, who had prepared extensively to exploit the machine's weakness in strategic play, was psychologically rattled. He later said that in that moment, he sensed "a new kind of intelligence" behind the moves. He lost the game and never fully recovered his composure. In Game 6, Kasparov played the Caro-Kann Defense, fell into a known trap, and resigned after just 19 moves — an astonishingly quick collapse for a world champion.

The aftermath was bitter and controversial. Kasparov demanded a rematch, but IBM refused and dismantled Deep Blue. The machine was never played again in public. Kasparov accused IBM of having human grandmasters intervene during the match, pointing to the mysterious quality of some of Deep Blue's moves. IBM denied the accusations and declined to release the machine's complete game logs, fueling conspiracy theories that persist to this day. The company's stock rose by $18 billion during and after the match — making it perhaps the most profitable chess game in history. Whatever the truth about Game 2, the symbolic significance of the match was undeniable: a machine had defeated humanity's greatest champion at the game that had long been considered the ultimate test of human intellect. The question was no longer whether machines could outthink humans at chess, but what, if anything, remained uniquely human.