Skip to content
Switch branches/tags

Latest commit

DTZ is given as moves until zeroing 50mr rule in the position before the move, subtracting one to give the distance after the chosen move.

Git stats


Failed to load latest commit information.


The name is an homage to VICE which I used as a base for this project. Development is inspired by Ethereal and Stockfish.

Weiss appears in the CCRL, CEGT, and FastGM rating lists, and can be seen competing in TCEC.

Weiss is part of the OpenBench testing framework. You can help us out by letting your idle CPUs run test games!

UCI settings

  • Hash

    The size of the hash table in MB.

  • Threads

    The number of threads to use for searching.

  • SyzygyPath

    Path to syzygy tablebase files.

  • MultiPV

    Output the N best lines when searching. Leave at 1 for best performance.

  • UCI_Chess960

    An option handled by your GUI. If true, Weiss will play Chess960.

  • NoobBook

    Allow Weiss to query and play moves suggested by noobpwnftw's online opening database.

  • NoobBookLimit

    Limit the use of NoobBook to the first x moves of the game. Only relevant with NoobBook set to true.

  • OnlineSyzygy

    Allow Weiss to query online 7 piece Syzygy tablebases hosted by lichess.