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makebearoff - generate a GNU Backgammon bearoff database


makebearoff [-HCcgnvh] -f filename [-t PxC] [-o P] [-s cache-size] [-O filename]


makebearoff generates GNU Backgammon bearoff databases, which are used to improve play in the endgame. It can generate either two-sided (exact) databases that tell precisely the chance of winning or one-sided (approximate) databases that provide a variety of probabilities looking at each side independently.

Bearoff databases can get quite large and can take a significant amount of time to generate for large numbers of chequers and/or points.


Write the bearoff database to filename. This option must be given.
Generate a two-sided bearoff database for P points and C chequers for each player. Be warned that the size of the database grows rapidly with larger numbers of points and chequers.
Generate a one-sided bearoff database for P points. One-sided bearoff databases are always generated for up to fifteen chequers.
Use a memory cache of size N while building the database. If the cache is smaller than the database size, database generation will be slower due to disk writes.
Reuse an already generated bearoff database. Any needed data already in this database will just be copied without regenerating it.
Do not write the normal bearoff database header.
Do not calculate cubeful equities for two-sided databases.
Do not compress one-sided databases.
Do not include gammon distributions in one-sided databases.
Rather than storing exact probabilities, approximate probabilities in a one-sided database with a normal distribution.
Show version information and exit.
Display usage and exit.


To generate a two-sided database for up to eight chequers on six points:

makebearoff -t 6x8 -f

Note that this database is 72MB in size. To generate a one-sided database for up to fifteen chequers on ten points:

makebearoff -o 10 -f

Note that this database is 118MB in size.


gnubg(6), bearoffdump(6)


Joseph Heled, Øystein Johansen, Jørn Thyssen, and Gary Wong, with the assistance of many others <>.

This manual page was written by Russ Allbery <>, for the Debian GNU/Linux system (but may be used by others). It may be redistributed and/or modified under the terms of version 2 of the GNU General Public License as published by the Free Software Foundation (the same license as GNU Backgammon).