HAHN_K@DMRHRZ11.BITNET (05/17/88)
Date: 17 May 1988, 14:54:30 CET From: HAHN_K at DMRHRZ11 To: INFO-ATARI16 at SCORE Next one: the other day I download GOBANG, the PD game, from the server. I *DO* like the program, it's well written and astonishingly clever (don't laugh!). I am interested in the promised 'official' version, or any other version that incorporates the tournament standards. Does anybody know of another or an improved / updated GO / Gobang - version ??? Take care, Klaus.
markov@ruuinf.UUCP (dr.m.h. overmars) (05/20/88)
I assume the GOBANG game you are talking about is the one I did write some time ago. The 'Official' option has never been included. Neither have I made any other improvement. One of the reasons is that I don't really know what the 'Official' rules are. (Somebody told me they existed but I never learned about them.) So if somebody can tell me ... I must say that I myself am also quite surprised how well the program plays. Maybe some history. Quite some time ago I implemented the well known game of putting stones on piles and getting four on a row. The technique used was straightforward backtracking with only limited cleverness. A friend of mine told me wheter I could do GOBANG in the same way. My reply was that this was a lot harder because the number of possible moves is very big and, hence, backtracking won't work. Because he continued asking I decided to program the thing completely without backtracking, just looking at the current situation. I was convinced that this would result in a program that was trivial to beat. When I got the first working version ready and started playing for the first time, to my surprise I was defeated in a few moves. Also the second and third time the program did win. Since then, only minor changes have been made to the strategy. Only in the top two level backtracking is added, and only in the case the computer can make rows of 4 (forcing the player to a particular move). Also some randomness was added to avoid similar games all the time. Since I wrote the program I beat most humans as well. the strategy of the program is so easy that you can play it by hand as well. Mark Overmars P.S. there is a UNIX version of the program as well, although it is an older version that is a bit less clever. It uses CURSES to handle the screen.