Deep Blue was a chess‑playing supercomputer designed and built at IBM in the 1990s to test and advance large‑scale search, specialized hardware, and computer‑chess methods; on 11 May 1997 it defeated Garry Kasparov, then the reigning World Chess Champion, in a regulation six‑game match by 3½–2½. IBM;
Associated Press;
IEEE Spectrum.
Origins and development
- –The project began with “ChipTest” at Carnegie Mellon University in 1985, led by Feng‑Hsiung Hsu with colleagues including Murray Campbell; it evolved into “Deep Thought” before the core team moved to IBM Research in 1989 to pursue a grand‑challenge machine aimed at world‑championship strength.
IBM;
Hsu, Campbell & Hoane, ICS 1995;
Britannica.
- –IBM’s internal contest renamed the system “Deep Blue” (a play on the company’s nickname, “Big Blue”), and successive prototypes competed in computer‑chess events and exhibitions en route to matches with Kasparov in 1996 and 1997.
Architecture and software
- –Deep Blue’s 1997 configuration was an IBM RS/6000 SP–based supercomputer with a massively parallel design centered on 30 compute nodes and 480 custom VLSI “chess chips,” enabling roughly 200 million position evaluations per second.
Computer History Museum;
IEEE Spectrum;
- –Each custom chip provided hardware‑accelerated move generation, search control, and evaluation primitives; the overall system used parallel alpha‑beta (α–β) search with extensions, transposition‑table techniques, and a sophisticated, parameterized evaluation function.
- –The team curated an opening “book” and also built an extended book by mining hundreds of thousands of grandmaster games to bias search toward historically strong continuations; endgame databases were employed and further strengthened for the 1997 rematch.
Communications of the ACM;
Matches with Kasparov
- –Philadelphia, 10–17 February 1996: Deep Blue won Game 1—the first time a machine beat a reigning champion under regular time controls—but Kasparov won the match 4–2.
WIRED (Feb. 10, 2011 retrospective).
- –New York City, 3–11 May 1997: a substantially upgraded system (“Deeper Blue” informally) defeated Kasparov 3½–2½; the deciding sixth game lasted only 19 moves and concluded on 11 May 1997.
Washington Post;
Associated Press.
Controversies and conditions
- –The match rules allowed between‑game program adjustments by the IBM team, a point later cited by commentators and Kasparov in debates over competitive conditions; IBM and independent reporting describe these changes as routine bug fixes and tuning within the agreed framework.
- –A widely discussed episode concerns a puzzling move from the 1997 match that some perceived as “human‑like”; years later, accounts from team members attributed it to a software glitch that produced a nonstandard choice, which may have affected Kasparov’s psychology.
FiveThirtyEight.
Aftermath and disposition
- –Following the 1997 victory, IBM retired the system; one Deep Blue rack was donated to the National Museum of American History (Smithsonian Institution) and another to the Computer History Museum, where they are cataloged as artifacts.
Smithsonian NMAH;
Legacy and influence
- –Deep Blue demonstrated the effectiveness of problem‑specific hardware and parallel search at scale, establishing a landmark in computer chess and symbolic AI.
- –IBM leveraged experience from Deep Blue in subsequent high‑performance computing and AI initiatives, including Blue Gene and Watson.
- –Later game‑playing breakthroughs such as DeepMind’s AlphaGo relied on different methods (deep neural networks plus Monte Carlo tree search), illustrating a methodological shift from handcrafted evaluation to learning‑based systems.
Nature (2016).
Team and contributors
- –Key IBM Research personnel included Feng‑Hsiung Hsu, Murray Campbell, and A. Joseph Hoane Jr., among others; external grandmaster consultants and analysts contributed to the opening preparation and testing.
Computer History Museum profile.