makebearoff - generate a GNU Backgammon bearoff database
makebearoff [-HCcgnvh] -f filename [-t PxC] [-o P] [-s cache-size] [-O
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.
-f filename, --outfile filename
Write the bearoff database to filename. This option must be
-t PxC, --two-sided PxC
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
-o P, --one-sided P
Generate a one-sided bearoff database for P points. One-sided
bearoff databases are always generated for up to fifteen
-s N, --xhash-size N
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.
-O filename, --old-bearoff filename
Reuse an already generated bearoff database. Any needed data
already in this database will just be copied without
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
Show version information and exit.
Display usage and exit.
To generate a two-sided database for up to eight chequers on six
makebearoff -t 6x8 -f gnubg_ts.bd
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 gnubg_os.bd
Note that this database is 118MB in size.
Joseph Heled, Øystein Johansen, Jørn Thyssen, and Gary Wong, with the
assistance of many others <firstname.lastname@example.org>.
This manual page was written by Russ Allbery <email@example.com>, 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).