=head1 NAME

gnugo - The GNU program to play the game of Go

=head1 SYNOPSIS

B<gnugo>
[B<--boardsize <num>>]
[B<--color <color>>]
[B<--handicap <num>>]
[B<--komi <num>>]
[B<--quiet>]
[B<-v, --version>]
[B<-h, --help>]
[B<--help debug>]
[B<--copyright>]
[B<--mode <mode>>]
[B<--replay <color>>]
[B<-l, --infile <filename>>]
[B<-L, --until <move>>]
[B<-o, --outfile <filename>>]
[B<--printsgf <filename>>]
[B<-D, --depth <num>>]
[B<-B, --backfill_depth <num>>]
[B<--score [estimate|finish|aftermath]> ]
[B<-a, --allpats>]
[B<-T, --printboard>]
[B<-d, --debug <level>>]
[B<-w, --worms>]
[B<-m, --moyo <level>>]
[B<-b, --benchmark num>]
[B<-t, --trace>]
[B<-r, --seed num>]

=head1 DESCRIPTION

GNU Go plays a game of Go against the user. It has many other features: it 
can play against itself or another program, analyse and score a recorded 
game. GNU Go is compliant with Go modem protocol, load and save game in
the Smart Game format. 

GNU Go default is a simple alpha-numeric board display, but you can use
a client such as B<CGoban>.

=head2 The game of Go

Go is a game of strategy between two players usually played on a
19x19 grid called B<goban>. The two players put black and white B<stones> on
the goban to enclose B<territory>. Go was invented about 4000 years ago in
ancient China. Other names for this game are (Chinese) B<Wei Chi>, (Korean)
B<Baduk> and (Ing) B<Goe>.

=head2 Playing a game in ASCII mode

To start a game with default options, just invoke "gnugo". The board will be
drawn at your terminal using ASCII letters.  In this mode, you can get help on
available commands by the B<h> key.  To play as Black with 4 stones handicap,
with a 0.5 komi, recording the game in the file record.sgf:

 gnugo --color black --handicap 4 --komi 0.5 -o record.sgf

=head2 Playing a game with CGoban

CGoban is a general purpose client program by Bill Shubert for
playing Go. It runs under X Window System with a beautiful resizeable
graphic display. To use GNU Go under X Window System, obtain the
most recent version of CGoban from Bill Shubert's web site

http://www.igoweb.org/~wms/comp/cgoban/index.html

Start CGoban. When the CGoban Control panel comes up, select `Go Modem.'
You will get the Go Modem Protocol Setup. Choose one (or both) of the
players to be ``Program,'' and fill out the box to the path to
gnugo. After clicking OK, you get the Game Setup window. Choose
``Rules Set'' to be Japanese (otherwise handicaps won't work). Set the
board size and handicap if you want. Click OK and you are ready to go.

In the Go Modem Protocol Setup window, when you specify the path
to GNU Go, you can give it command line options, such as --quiet
to suppress most messages. Since the Go Modem Protocol preempts
standard I/O, other messages are sent to stderr, even if they are
not error messages. These will appear in the terminal from which
you started CGoban. 

=head2 Scoring system

The game stops when both players pass. GNU Go will attempt to
compute and report the score to you. It may occasionally make
mistakes due to wrong evaluation of the status of a group. You
can check the score as follows. In ASCII mode, at the end of
the game, stones believed dead are marked in lower case letters,
and you have the option of toggling their status before counting.
Using CGoban, you may use CGoban's counting facility to count
the game using either Japanese or Chinese rules.

=head2 Viewing a stored game

gnugo B<-l> filename.sgf --mode ascii

loads filename.sgf and lets you navigate through the game by using the
commands I<forward>, I<back>, I<goto> and I<last>.
It is not possible to navigate through variations in ascii mode.
You may also use CGoban to view stored games. CGoban can navigate
variations.

=head2 Documentation

The files in the F<doc> directory contain detailed documentation about
debugging options and internal program structure. Other documentation may
be found in comments throughout the source code.

=head2 Go Modem Protocol

The Go Modem Protocol is a standard interface between Go programs and
graphical display. 

The Go Modem Protocol was developed by Bruce Wilcox with input from
David Fotland, Anders Kierulf and others. Any Go program *should*
use this protocol since it is standard. Since CGoban supports this
protocol, the user interface for any Go program can be done
entirely through CGoban. Using the Go Modem Protocol, you can play
with another computer running a different program (even on a
different operating system) using a modem, a serial cable or over
the internet if the other program also supports the protocol. You
can also communicate with the Go servers using CGoban.

=head2 Smart Game Format

Games (with comments, variations and other features) can be
stored in the Smart Game Format (SGF). This format originated in
Anders Kierulf's program Smart Go. Martin Muller and Arno
Hollosi developed the current standard, which may be found
at 

http://www.red-bean.com/sgf/

GNU Go supports the Smart Game Format.

=head1 OPTIONS

=head2 Main options

B<--mode I<mode>>

force the playing mode (I<ascii'>, I<gtp> or I<gmp>). Default is 
ASCII. If no terminal is detected GMP (Go Modem Protocol) will be assumed.

B<--replay I<color>>

replay the game generating moves for color, where color is I<white>,
I<black>, or I<both>. (requires B<-l>)

B<--quiet>

Don't print copyright and other informational messages.

B<-l, --infile I<file>>

Load the SGF file (to score or analyze a recorded game).

B<-L, --until I<move>>

Stop loading just before I<move> is played (e.g. 154 or L10).

B<-o, --outfile I<file>>

Save the played game to I<file> in SGF format.

=head2 Game Options: 

B<--boardsize I<num>>

Set the board size to use (1-19). Default is 19, other common formats are
13 and 9.

B<--color I<color>>

Choose your color (I<black> or I<white>). Black plays first, White gets
the komi compensation.

B<--handicap I<num>>

Set the number of handicap stones.

B<--komi I<num>>

Set the komi (points given to white player to compensate advantage of the 
first move, usually 5.5 or 0.5). Default is 5.5.

=head2 Informative Output:

B<-v, --version>

Display the version of GNU Go. 

B<-h, --help>

Display help message.

B<--help debug>

Display help about debugging options. 

B<--copyright>

Display copyright notice.

=head2 Debugging and advanced options:

B<-T, --printboard>

Show board each move.

B<--level I<num>>

Level of play. (default 10; smaller=faster, weaker).

B<-b, --benchmark I<num>>

Benchmarking mode - can be used with B<-l>.

B<-t, --trace>

Verbose tracing (use twice or more to trace reading).

B<-r, --seed I<num>>

Set random number seed.

B<--score [I<estimate|finish|aftermath>]>

Count or estimate territory of the input file. Usage:

B<gnugo --score estimate -l filename>

Loads the SGF file and estimates the score by measuring the
influence. Use with B<-L> if you want the estimate somewhere else than
at the end of the file.

B<gnugo --score finish -l filename>

Loads the SGF file and gnugo continues to play by itself up to the
very end. Then the winner is determined by counting the territory.

B<gnugo --score aftermath -l filename>

Similar to B<--score finish> except that a more accurate but slower
algorithm is used to determine the final status of the groups.

If the option B<-o outputfilename> is provided, 
the results will also be written as comment at the end of the output file.

B<--printsgf I<outfile>>

Load SGF file, output final position (requires B<-l>).

=head1 BUGS

If you find a bug, please send the SGF output file to gnugo@gnu.org
together with a description of the bug.

=cut