makebearoff — generate a GNU Backgammon bearoff database
Synopsismakebearoff [-HCcgnvh] -f filename [-t PxC] [-o P] [-s cache-size] [-O filename]
Descriptionmakebearoff 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.
- -v, --version
- Show version information and exit.
- -h, --help
- Display usage and exit.
ExamplesTo 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.