Unveiling Stockfish 17: The Latest Version of the World's Strongest Chess Engine Revealed

Quality of chess play
In tests against Stockfish 16, this release brings an Elo gain of up to 46 points and wins up to 4.5 times more game pairs than it loses. In practice, high-quality moves are now found in less time, with a user upgrading from Stockfish 14 being able to analyze games at least 6 times faster with Stockfish 17 while maintaining roughly the same quality.

During this development period, Stockfish won its 9th consecutive first place in the main league of the Top Chess Engine Championship (TCEC), and the 24th consecutive first place in the main events (bullet, blitz, and rapid) of the Computer Chess Championship (CCC).

Update highlights
Improved engine lines
This release introduces principal variations (PVs) that are more informative for mate and decisive table base (TB) scores. In both cases, the PV will contain all moves up to checkmate. For mate scores, the PV shown is the best variation known to the engine at that point, while for table base wins, it follows, based on the TB, a sequence of moves that preserves the game outcome to checkmate.

NUMA performance optimization
For high-end computers with multiple CPUs (typically a dual-socket architecture with 100+ cores), this release automatically improves performance with a NumaPolicy setting that optimizes non-uniform memory access (NUMA). Although typical consumer hardware will not benefit, speedups of up to 2.8x have been measured.