Software Board-Games - Backgamm

Description:

Backgammon is a program written entirely in 80X86 assembly language to run on IBM compatible computers.
Using pattern recognition techniques developed to guide 'smart' weapons similar to those use in the recent Gulf War, Backgammon plays the game entirely without rules other than those specific to the play of the game.
That is, it has no rules of thumb for deciding which of the many possible moves it will make at each turn.
Rather, it examines each of the possible outcomes (there are usually fewer than 40 except in rare cases such as double ones) and uses a complex evaluation algorithm to assign a value to each of them and then takes the move with the highest value.
Actually, to make its play more interesting, there is also a 'random factor' used which keeps it from playing too predictably, but this factor gets smaller and smaller as you choose to play at higher and higher skill levels. Similarly, its doubling (gambling) behavior is guided entirely by pattern recognition routines rather than explicit rules.
All in all, BACKGAMMON examines about forty variables when making its decisions.
These are further refined by two parameters, the stage of the game (i.e.
how far into the game are we) and the relative standing of the opponents (i.e.
who's ahead).
The variables are things like the bunching of the pieces, the size of blockades, the evenness of piece distribution, etc. At lower levels, BACKGAMMON tends to play conservatively, trying to minimize the number of runners and keep its pieces together.
At higher levels, it plays much more aggressively, trying to get an early advantage and quickly double the stakes.
It also hangs on tenaciously to 'lost' games and will often surprise you with a roaring comeback.
You may decide that the levels do not represent skill levels as much as different philosophies of play and, as such, it is just as rewarding to play BACKGAMMON at level zero as at level nine.
Try starting at the lower levels and moving upward.
After a while, you may find yourself switching levels randomly to get a different type of game on different days. BACKGAMMON was developed in an unusual fashion.
The earliest experimental versions 'learned' to play by playing against themselves! After the mechanics of following the rules of the game were programmed in, the two sides were each programmed with a slightly different algorithms and set to playing (without human intervention) against one another for thousands of games or matches. It was then possible to decide, with great statistical precision, which of the two algorithms were superior. In this manner, the program was gradually improved, based upon suggestions from human testers and theoretical ideas gleaned from books on the subject. Periodically, it was necessary to pit BACKGAMMON against a group of human testers.
If the automatic procedure was used too long without this kind of a reality check, it seemed that the machine play would begin to diverge into strange and unpredictable behavior that wasn't necessarily good play, but merely 'better' play than its mechanical opponent's algorithm.
Sort of a machine La-La land. The result is the program you have in hand.
If you find it an enjoyable and challenging backgammon opponent, please consider paying the registration fee. This modest sum of money (by computer program standards) will get you phone support, periodic updates and enhancements, the knowledge that you are contributing to the advancement of computer game playing and the satisfaction of rewarding a job well done! Work in progress includes a higher resolution product for EGA and VGA monitors.
On the other hand if you can't afford it, please have a ball on me!