Prophet is a chess playing program that I’ve worked on in fits and starts since 2000. It’s a console based program, or “engine.” To play it you’d probably want to install Winboard or some other Winboard compatible user interface.


You can download the source code as well as binaries for Windows and Linux from the Prophet Github repo:

Prophet is distributed under the MIT license.


The first version of Prophet was written around the year 2000 while I was an undergraduate. It was a conventional chess engine, utilizing a depth first alpha-beta search with iterative deepening. I used this version to do some not-so-successful experimentation with TDLeaf (a form of temporal difference learning) and wrote about it in this abstract.

The second version was released in early 2007. I was in graduate school at that time and was using Prophet as a test bed for various parallel search algorithms. I continued to work on this version until shortly after finishing graduate school in 2008. If you’re interested you can read about it in this paper.

After that, Prophet lie dormant for a few years until 2011 when I started a second complete rewrite. By this point I had learned the importance of test driven design and wanted to apply that to Prophet. Life got busy again and the project lie dormant for several more years before it was even released. Prophet3 never achieved functional parity with Prophet2. I never implemented the parallel search, and there are some evaluation terms that were never ported. Despite that, I think it is a better program overall.

Development on Prophet4 began in June 2019 and released in Fall 2021.  It was a tremendous amount of work but I think the effort was worth it.  All the design goals were met, providing a solid foundation for years to come.

How Strong is it?

The CCRL Blitz List shows Prophet 4.3 to have a rating of 2546 as of April 2, 2023.


Prophet has participated in some well publicized computer chess tournaments, but none recently.  These days it’s mostly informal blitz tourneys and tourneys conducted by private testers.  I hope that will change soon.