Dabble is a computer program that uses alpha-beta search to play dots and boxes.  Its understanding of the game is minimal; it knows about chains and double-crosses but nothing else.  Despite this, Dabble is able to play at a reasonable skill level; higher level strategies emerge from brute-force search.

Dabble was written by  J.P. Grossman and introduced at the second Combinatorial Game Theory Research Workshop, held at the Mathematical Sciences Research Institute, July 24-28, 2000.

September 6, 2001: A bug causing the program to crash has finally been tracked down. An updated version (version 1.3) is now available which fixes this.

February 12, 2004: Thanks to Glenn Rhoads for uncovering a small bug in the code. The .zip files have been updated with a fix.


dabble.zip (40K) Two versions of the dabble executable for windows and some sample games.  Please read readme.txt as it explains the difference between the two versions.
dabble_source.zip (112K) The dabble source code and associated MSVC++ 6.0 project files. This code is licensed under the GNU General Public License
 mfc42.zip (458K) If you get a strange error message involving mfc42.dll when you try to run dabble, you may need to unzip this file in the directory where you placed dabble.

Learning More about Dots and Boxes

There is a rich mathematical theory behind this simple children's game.  To learn more about it, I highly recommend Elwyn Berlekamp's new book, The Dots and Boxes Game - Sophisticated Child's Play, published by A. K. Peters.  For those who know about nimstring, Freddy Mang has written a program to compute the nimstring value of a strings and coins problem.  It can be accessed online at http://www-cad.eecs.berkeley.edu/~fmang/nimstring/index.html