Brainfish for Windows
Brainfish for Windows

Brainfish for Windows

Brainfish is a standard Stockfish chess engine extended by a general book format, which is capable of handling a reduced part of Cerebellum, which is an innovative chess opening and playing book. In BrainFish the Book moves are only used in engine games, not in analysis mode.

All moves in the distributed book Cerebellum_light.bin generated by Cerebellum where calculated by using Stockfish as analysis engine, without using statistics. Then those moves where again recalculated by the Cerebellum Library using a graph algorithm which makes all scores in the library consistent. Consistent scores means for example when the starting position has a score of 0.2 and a best move is 1.e4, the position after 1.e4 must have the score -0.2. Additional some others properties are found like the best main line for a position and possible Transitions.

That means when Brainfish is playing, it plays like Stockfish regarding the evaluation, only a much higher skill level. The lines in Cerebellum_light.bin are in some cases reaching the late middlegame and endgame. Pondering is only active after the last move out of the book has been played

BrainFish is licensed under the GPL, which includes the access code to the general book format. </p>

Brainfish is delivered in 3 different compiled Versions:

  • _X64 for older 64 bit Processors.</li>

  • _modern for modern 64 bit Processors like Nehalem, Sandy Bridge, Ivy Bridge.</li>

  • _bmi2 for the latest 64 bit Processors like Intel© Haswell, Broadwell, Skylake. and Amd© Excavator, Zen.</li>

There are three additional UCI options:

  • "BookPath", default = empty
    Path to the BrainFish Book.

  • "Book Move2 Probability", default = 0, min = 0, max = 100
    For some positions, a second possible move for a specific position ist contained in the library, for example after 1.e4 not only 1. ..e5, but also 1. ..c5 That move is played with a probability according to "Book Move2 Probability", where 100 means always and 0 never.
    Brain Fish can of course handle also moves or openings which are never played by the book, for example 1. ..e6. You can play such openings with using a Standard opening book which for example plays only 1. ..e6 as black and then stops.

  • "Large Pages" default = false
    Activates Large Pages support for the Hashtable with faster access. May work only for some time after a windows restart because of memory fragmentation. The standard memory allocation fallback is activated automatically. Additional user rights like starting in Administrator mode may be necessary.

Additional remarks and Feedback

Brainfish should be able to compete with the best existing opening librarys, which means u can use it for engine tournaments without an opening book.

For feedback or if you have lines (for example from a lost game) that should be included in the book, you can send them to Brainfish (at)