This is an old chess engine that saw more actove development during 2000-2003. The code is messy and sparsely commented. It is also very weak compared with other engines but still very strong compared with most humans.

Compilation follows the usual ./confgure; make. make install will install the binary but it is easier to just copy it where you need it.

To run using xboard as a frontend, use
xboard -fcp "smallpotato <options>"
To run it through WinBoard, you will need to add something like the following to your winboard.ini:
/fcp "smallpotato <options>" /fd "full\path\to\smallpotato\directory"
/scp "smallpotato <options>" /sd "full\path\to\smallpotato\directory"
If you are using some other interface then you should read its documentation.

You will also need an opening book. You can get one from http://organicrobot.com/smallpotato/book64.opn.bz2 for 64-bit systems, http://organicrobot.com/smallpotato/book32.opn.bz2 for 32-bit or you can make your own by looking at makebookfrompgn.py in the tools subdirectory. The book above was created by feeding Arturo Ochoa's collection of GM games into it.

The preferred method of configuration is to use the configuration file. "sp.rc" is first looked for, and if that doesn't exist, "sp.ini" is opened. You can also specify a configuration file through the -config commandline switch. A default sp.rc is supplied with instructions on what each switch means.

It is also almost fully configurable through the command line. Run "smallpotato -help" to list them all, or read doc/help.txt if you don't see anything when you run it (some windows versions).

Most of the program control is done through commands during the running of the program (eg to create or modify a book). Read commands.txt in the doc directory for more information on these.

For the opening book, Small Potato uses gdbm which you can get from http://www.gnu.org.ua/software/gdbm/
Anything 1.x post 1.8.3 should work. Due to gdbm files not being portable between 32- and 64-bit systems, you'll need a different opening book depending on your system.

Small Potato uses clig (version 1.9.9 or greater) to take care of the command line handling, but it isn't needed unless you are planning to change the command-line options. It can be gotten from: http://wsd.iitb.fhg.de/~kir/clighome/

Small Potato used to be called unches. It extremely rarely still plays under that name in FICS.

Ideas were stolen/borrowed from lots of places. Some of them follow:

• Crafty
• F.D. Laramée, and his how-to-write-a-chess-program tutorial from gamedev.net (http://www.gamedev.net/reference/articles/article1014.asp)
• GNU Chess
• Alpha-Beta & TT by Aske Plaat, Jonathan Schaeffer, Wim Pijls and Arie de Bruin (http://www.cs.vu.nl/~aske/Papers/tr9417.pdf)
• MTD(f) - A Minimax Algorithm faster than NegaScout, by Aske Plaat
• Research Re: search & Re-search by Aske Plaat (PhD Thesis) (http://www.cs.vu.nl/~aske/Papers/abstr-ks.html)
• Computer Chess Web Site by Bruise Moreland http://www.seanet.com/~brucemo/chess.htm
• Pepito http://www.winboardengines.de/pepito/
• Amy http://www.stethojupi.de/software.html
• KnightCap http://samba.org/KnightCap/ and http://syseng.anu.edu.au/~jon/papers/knightcap.ps.gz
• The Design and Implementation of the Rookie 2.0 Chess Playing Program by M.N.J. van Kervinck at http://brick.bitpit.net/~marcelk/2002/marcelk-thesis.ps.gz
• Rebel's secrets by Ed Schröder at http://members.home.nl/matador/chess840.htm

Comments, code, bugreports and patches are welcome.

Copyright (C) 2000 Alejandro Dubrovsky

Small Potato is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA