Deep Blue defeats a reigning world chess champion
IBM's brute-force search machine beats Kasparov in a rematch watched worldwide
Quick facts
- Opponent
- Garry Kasparov, reigning world chess champion
- Result
- Deep Blue won 3.5-2.5
- Processing
- 200 million positions per second, 32 processors
What happened
IBM's Deep Blue, a chess computer using 32 processors and 216 custom chess chips, played a six-game rematch against reigning world champion Garry Kasparov at the Equitable Center in New York in May 1997, a year after Kasparov had beaten an earlier version of the machine. Deep Blue searched up to 200 million chess positions per second, evaluating moves through brute-force lookahead rather than any learned strategic sense, aided by hand-tuned evaluation functions built with input from chess grandmasters. Kasparov won game one, Deep Blue took game two, three games were drawn, and Deep Blue won the decisive sixth game, taking the match 3.5 to 2.5. Kasparov later said the loss unsettled him enough that he suspected human interference, an accusation IBM denied and that has never been substantiated.
Why it matters
Deep Blue was the first computer to beat a reigning world chess champion in a standard match, a milestone widely read at the time as a symbolic test of whether machines could catch up to human intellect, even though its brute-force search method bore little resemblance to how later AI systems would learn.
How we know
IBM's own corporate history page documents the match's results and Deep Blue's processing power; IEEE Spectrum's account independently corroborates the 200-million-positions-per-second figure and the machine's chess-specific hardware.
Sources
- IBM Corporate History. Deep Blue · Primary source (author-declared)ibm.com · Cited as a "primary" source (no stronger domain match). · Link is live and its text matches the event's key terms (Jul 2026)
- IEEE Spectrum. How IBM's Deep Blue Beat World Champion Chess Player Garry Kasparov · Peer-reviewedspectrum.ieee.org · The domain "spectrum.ieee.org" is on our Peer-reviewed registry. · Link is live and its text matches the event's key terms (Jul 2026)
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