The following books and online pages inspired me during the design and implementation of the
project.
Literature concerning zero sum 2-player boardgame programming:
To make the computer play strongly it is crucial to complement the evaluation function with some
game related rules:
[1] Expert Play in Connect Four, James D. Allen 1990
http://www.cwi.nl/~tromp/c4.html
This is a must read, if you want to know more about odd, even and double threats and the like:
[2] A Knowledge based approach of Connect Four, Victor Allis 1988
connect4.pdf
A powerful extension of Minimax is the MTD(f) algorithm. A paper that explains its amazing behavior
can be found here:
[3] A Minimax Algorithm faster than Negascout, Aske Plaat 1997
http://www.cs.vu.nl/~aske/mtdf.html
A well written and useful introduction into chess programming is at hand by Bruce Moreland.
The programming aspects hold for general boardgame programming and can be easily adopted.
[4] http://www.seanet.com/~brucemo/topics/topics.htm
Martin Fierz offers a tutorial that covers all topics as well.
[5]
http://www.fierz.ch/strategy1.htm
Other Resources:
A comprehensive collection of connect four programs is available by Andreas Herrmann. The playing strength
of these programs has been rated and classified. This site is in German and highly recommended.
[1] http://brettspiele.sanher.de/4gewinnt.htm
Recommendable Connect Four Games:
There are other Connect Four games available that can play perfectly or at least very strongly:
[1] Velena by Giuliano Bertoletti
[2] Four in a row by Martin Fierz
[3] Fyrad by Peter Sunna
[4] Mustrum by Lars Bremer
[5] Four wins by FutureVision
[6] Connect Four by Mike Johnson as Applet Version
[7] Four or more by Bauer & Schweitzer
