1MAKEBEAROFF(6) Games Manual MAKEBEAROFF(6)
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6 makebearoff - generate a GNU Backgammon bearoff database
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9 makebearoff [-HCcgnvh] -f filename [-t PxC] [-o P] [-s cache-size] [-O
10 filename]
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13 makebearoff generates GNU Backgammon bearoff databases, which are used
14 to improve play in the endgame. It can generate either two-sided
15 (exact) databases that tell precisely the chance of winning or one-
16 sided (approximate) databases that provide a variety of probabilities
17 looking at each side independently.
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19 Bearoff databases can get quite large and can take a significant amount
20 of time to generate for large numbers of chequers and/or points.
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23 -f filename, --outfile filename
24 Write the bearoff database to filename. This option must be
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27 -t PxC, --two-sided PxC
28 Generate a two-sided bearoff database for P points and C che‐
29 quers for each player. Be warned that the size of the database
30 grows rapidly with larger numbers of points and chequers.
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32 -o P, --one-sided P
33 Generate a one-sided bearoff database for P points. One-sided
34 bearoff databases are always generated for up to fifteen che‐
35 quers.
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37 -s N, --xhash-size N
38 Use a memory cache of size N while building the database. If
39 the cache is smaller than the database size, database generation
40 will be slower due to disk writes.
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42 -O filename, --old-bearoff filename
43 Reuse an already generated bearoff database. Any needed data
44 already in this database will just be copied without regenerat‐
45 ing it.
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47 -H, --no-header
48 Do not write the normal bearoff database header.
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50 -C, --no-cubeful
51 Do not calculate cubeful equities for two-sided databases.
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53 -c, --no-compress
54 Do not compress one-sided databases.
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56 -g, --no-gammons
57 Do not include gammon distributions in one-sided databases.
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59 -n, --normal-dist
60 Rather than storing exact probabilities, approximate probabili‐
61 ties in a one-sided database with a normal distribution.
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63 -v, --version
64 Show version information and exit.
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66 -h, --help
67 Display usage and exit.
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70 To generate a two-sided database for up to eight chequers on six
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73 makebearoff -t 6x8 -f gnubg_ts.bd
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75 Note that this database is 72MB in size. To generate a one-sided data‐
76 base for up to fifteen chequers on ten points:
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78 makebearoff -o 10 -f gnubg_os.bd
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80 Note that this database is 118MB in size.
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83 gnubg(6), bearoffdump(6)
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86 Joseph Heled, Øystein Johansen, Jørn Thyssen, and Gary Wong, with the
87 assistance of many others <bug-gnubg@gnu.org>.
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89 This manual page was written by Russ Allbery <rra@debian.org>, for the
90 Debian GNU/Linux system (but may be used by others). It may be redis‐
91 tributed and/or modified under the terms of version 2 of the GNU Gen‐
92 eral Public License as published by the Free Software Foundation (the
93 same license as GNU Backgammon).
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97 2006-01-15 MAKEBEAROFF(6)