Subject: Abalone Implementation

From: [email-masked] (Ulrich Mayring)
Date: Sun, 18 Apr 93 12:38:03 MET DST

Hello whoever you are,

I have been told this address is one, where I could get onto an Aabalone
mailing list and talk to some other Abalone enthusiasts. Please forgive me
if you are not the right person to talk to, maybe you could then forward
this letter provided you know whereto.

You may be interested in the following (prepared and thus unpersonal) text:

Well, here's the story on how far we got with implementing Abalone.

I bought the game, liked it and told my friends about it. One of them, a fairly
expert Pascal coder immediately set his heart towards a computer implementation.
He got pretty far by now, however, the program is still in a somewhat un-
functional state. Features included are:

Can be run as a PBM-game, which we will at least try to get launched, since it
keeps a very interesting hall of fame of all players, which is updated after
every move of either of the players. Many parameters are included for intro-
ducing alternative rules, since standard Abalone seems to run about 200 moves
a game, which would make it somehow lengthy for a PBM-game.

Some of the parameters, which can be changed to produce different sets of 
rules, are:
-Number of players (two or three per board)
-Board size (It will, however, always be a hexagon)
-Number of pieces at start of game
-Number of pieces you need to throw out in order to win the game.
-Length of chains (in standard Abalone you cannot move more than 3 pieces in a
 row and a chain of 3 pieces is always secure. Here we can change that number
 to 4, 5 or more, or even down to 2.)

The game can also be run as an automaton you can play against. This is what
we currently are working on. We implemented a Minimax algorithm with Alpha-
Beta Pruning and did some routines in assembler, so right now search depth 3
has a time penalty of 20 seconds. This can be further optimized once we have
a reasonable board analysis, but we still struggle on some of the parameters
It is not easy at all to come up with a set of useful parameters that really
tell if the game situation is 'good' or 'bad' for the player.
The automaton is already playing very well, even at search depth 1, where it
instantly moves. Once we get the parameters sorted out, we expect depth 3,
which already beats depth 1, to be strong enough to beat us sometimes.

Games are saved in DBaseIII format, so you can look at them with DBase and
easily build up a large library of games. We also made a viewer, which takes
any game in DBaseIII format and lets you toggle moves forward and backwards
with the cursor keys. The board for the viewer and the automaton is shown
in a pretty VGA-graphic and moves can be entered with the mouse.

If there are any Abalones out there, which are free to look at or at least for
a reasonable price, we would very much like to look into them and eventually
match our automaton against them.

(BTW: Copyright issues are still unresolved, we'd be interested in any info we
could get on that, too)

     Ulrich Mayring
EMail: [email-masked]