Inanis 1.2.0 released

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Another major update of the Inanis chess engine: better Syzygy support, performance and stability improvement.

Strength: 2850 Elo, Link:


  • Added integration with Fathom library to better support Syzygy tablebases
  • Added “tbhits” to the search output
  • Added “avg_game_phase” parameter to “tunerset” command
  • Added “syzygy” and “bindgen” as switchable Cargo features
  • Added information about captures, en passants, castles, promotions and checks in perft’s output
  • Added attackers/defenders cache
  • Added killer moves as separate move generator phase
  • Removed unnecessary check detection in null move pruning
  • Removed redundant abort flag check
  • Removed underpromotions in qsearch
  • Reduced binary size by removing dependencies and replacing them with custom implementation
  • Renamed “test” command to “testset”
  • Simplified evaluation by reducing the number of score taperings
  • Improved build process
  • Improved benchmark output
  • Improved allocation of all hashtables, now their size will always be a power of 2 for better performance
  • Improved king safety evaluation by taking a number of attacked adjacent fields more serious
  • Improved overall performance by a lot of minor refactors and adjustments
  • Improved game phase evaluation
  • Improved killer heuristic
  • Improved history table aging
  • Improved reduction formula in null move pruning
  • Fixed a few “tunerset” command bugs related to the game phase
  • Fixed PGN parser when there were no spaces between dots and moves
  • Fixed invalid evaluation of doubled passing pawns
  • Fixed invalid cut-offs statistics
  • Fixed qsearch failing hard instead of failing soft

History version

VersionRelease dateEloDescription
1.2.015-01-20232850Better Syzygy support, performance and stability improvement
1.1.114-08-20222800A bunch of fixes for reported issues, stability improvement
1.1.031-07-20222800Syzygy tablebases, MultiPV, adjusted evaluation
1.0.105-04-20222750A bunch of fixes for reported issues, stability improvement
1.0.002-04-20222750Initial release