# From hvrunix!vu-vlsi!cbmvax!bpa!burdvax!sdcrdcf!oberon!cit-vax!ames!ucbcad!ucbvax!sdcsvax!ucsdhub!hp-sdd!hplabs!hpcea!hpisla!hpltca!jhs Wed Apr 29 16:19:51 1987
# Path: swatsun!hvrunix!vu-vlsi!cbmvax!bpa!burdvax!sdcrdcf!oberon!cit-vax!ames!ucbcad!ucbvax!sdcsvax!ucsdhub!hp-sdd!hplabs!hpcea!hpisla!hpltca!jhs
# From: jhs@hpltca.HP.COM (John Stanback)
# Newsgroups: net.sources.games
# Subject: C source for CHESS
# Message-ID: <2320001@hpltca.HP.COM>
# Date: 29 Apr 87 20:19:51 GMT
# Organization: H P, Colorado Integrated Circuits Div., Loveland, CO
# Lines: 2660
# 
# 
# C source for CHESS
# 
# Here is a shar script containing source code in 'C' for a chess 
# program I've written. The following files are included: 
#   1. chess.c   : C source for CHESS
#   2. chess.opn : Opening Library
#   3. chess.001 : Sample problem
#   
# The file chess.c must be compiled with the -lcurses option. The 
# code is pretty generic (I think) and hopefully will run on a wide 
# variety of machines. The help command gives a list of the options
# available.  To test out the program, enter 'get' and respond to
# the file name prompt with 'chess.001'.  Type 'switch' and the
# computer should find mate in 4 with Nf7.  This takes a few seconds
# on an HP350 computer.
# 
# The program plays a fairly respectable game of chess, although it 
# is not competetive with a state-of-the art commercial program. The 
# search rate is typically 100-300 nodes/sec. on an HP Vectra (8 Mhz. 
# 286) and about 300-900 nodes/sec. on an HP 350 (25 Mhz. 68020). I 
# am interested to find out what is achieved on other machines. I 
# would also be interested in any comments on playing strength, 
# weaknesses or bugs in the program, and suggested improvements in 
# the algorithm. 
# 
# Here are a few comments on the program:
# 
# 1. Opening Library
#      I'm a terrible chess player and don't know anything about 
#      openings. I copied 70-80 random lines of play from MCO into 
#      the file chess.opn. I think there are a few mistakes in the 
#      translation. If anyone generates a better library please let 
#      me know. 
#      
# 2. Positional Heuristics
#      I think that improvement in this area would help the program 
#      quite a bit. In most situations the computer cannot do
#      anything forceful and the choice of a move is based on 
#      positional aspects. I haven't spent a lot of time on the 
#      heuristics and many times the program has no idea of what is 
#      happening and how to proceed. Perhaps optimizing the values of 
#      the existing heuristics would help, but to get a major 
#      improvement I think more chess knowledge will be necessary. 
#      
# 3. Search Algorithm
#      This program uses a full-width alpha-beta searching technique 
#      with depth extensions on checks, check evasions, pawn promotion
#      threats and threats to multiple pieces. Capture sequences are
#      handled by a separate search routine. I imagine that much more
#      efficient search routines exist, and would be interested to hear
#      of any. Refinements of the search extension heuristics (similar
#      to the extensions for pawn promotion threats) could have a major 
#      effect on the programs ability. 
#      
# 4. Move Generation
#      There are probably better ways to do this, but they would 
#      likely change the data structure drastically and necessitate 
#      a complete re-write. Maybe some good hacks would speed things 
#      up, the ataks function would be the best place to start.
#       
# 
# This is a shell archive.  Remove anything before this line,
# then unpack it by saving it in a file and typing "sh file".
#
# Wrapped by jhs at hpltca on Wed Apr 29 13:19:09 1987
#
# This archive contains:
#	chess.c		chess.opn	chess.001	
#