makebearoff - Man Page

makebearoff [-HCcgnh] -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.

-f filename, --outfile filename

Write the bearoff database to filename. This option must be given.

-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 chequers.

-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 chequers.

-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 regenerating it.

-H,  --no-header

Do not write the normal bearoff database header.

-C,  --no-cubeful

Do not calculate cubeful equities for two-sided databases.

-c,  --no-compress

Do not compress one-sided databases.

-g,  --no-gammons

Do not include gammon distributions in one-sided databases.

-n,  --normal-dist

Rather than storing exact probabilities, approximate probabilities in a one-sided database with a normal distribution.

-h,  --help

Display usage and exit.

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

    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.

gnubg(6), bearoffdump(6)

Joseph Heled, Øystein Johansen, Jørn Thyssen, and Gary Wong, with the assistance of many others <bug-gnubg@gnu.org>.

This manual page was written by Russ Allbery <rra@debian.org>, 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).