Houdini (chess)


Houdini is a UCI chess engine developed by Belgian programmer Robert Houdart. It is influenced by open-source engines IPPOLIT/RobboLito, Stockfish, and Crafty. Earlier versions are free for non-commercial use, but later versions are commercial. As of October 2019, Houdini 6 is the fourth highest-rated chess engine on major chess engine rating lists, behind Stockfish, Leela Chess Zero and Komodo.

Playing style

Chess commentator and video annotator CM Tryfon Gavriel compared Houdini's playing style to that of the Romantic Era of chess, where an attacking, sacrificial style was predominant. According to Robert Houdart, Houdini's advantage against other top engines is in its handling of piece mobility, which is why it "favors aggressive play that tries to win the game".

Version history

The latest stable release of Houdini comes in two versions: Houdini 6 Standard and Houdini 6 Pro. Houdini 6 Pro supports up to 128 processor cores, 128 GB of RAM and is NUMA-aware, Houdini 5 Standard only supports up to 8 processor cores, 4 GB of hash and is not NUMA-aware. As with many other UCI engines, Houdini comes with no GUI, so a chess GUI is needed for running the engine. Houdini 5 uses calibrated evaluations in which engine scores correlate directly with the win expectancy in the position.

Competition results

Houdini is one of the most successful engines in the TCEC tournament, which is often regarded as the Unofficial World Computer Chess Championship, with four championship wins to date.

Notable games