Deep Blue

Deep Blue was a chess-playing computer developed by IBM that defeated world champion Garry Kasparov in a six-game match in 1997, becoming the first computer system to defeat a reigning world champion under standard tournament conditions. The system was a massively parallel supercomputer optimized for brute-force search, capable of evaluating 200 million positions per second, and it employed an evaluation function that encoded substantial human chess knowledge — opening books, endgame databases, and heuristic rules crafted by grandmasters.

Deep Blue occupies a pivotal position in the history of AI as the last great triumph of the knowledge-based approach. Its evaluation function was not learned from data but engineered by human experts. Its opening book was curated by human grandmasters. Its endgame databases were computed exhaustively but organized by human understanding of endgame structure. The victory was a milestone, but it was a milestone for human knowledge encoded in silicon, not for machine learning. The system that eventually surpassed chess — AlphaZero's purely neural, self-taught approach — did not build on Deep Blue's architecture. It replaced it entirely.