IN MAY 1997, an IBM supercomputer known as Deep Blue was ready to stand against world champion Garry Kasparov, who had once bragged he would never lose to a machine.
The champion and computer met at the Equitable Center in New York, with cameras running, press in attendance and millions watching the outcome. The odds of Deep Blue winning were not certain, but the science was solid. The IBMers knew their machine could explore up to 200 million possible chess positions per second.
On May 11th, 1997, Deep Blue did what at the time seemed impossible: it defeated the chess world champion Garry Kasparov at his own game.
Kasparov and other chess masters blamed the defeat on a single move made by the IBM machine. Either at the end of the first game or the beginning of the second, depending on who’s telling the story, the computer made a sacrifice that seemed to hint at its long-term strategy.
Kasparov and many others thought the move was too sophisticated for a computer, suggesting there had been some sort of human intervention during the game. “It was an incredibly refined move, of defending while ahead to cut out any hint of counter moves,” grand-master Yasser Seirawan told, “and it sent Garry into a tizzy.”
Fifteen years later, one of Big Blue’s designers says the move was the result of a bug in Deep Blue’s software.