This article would not have been possible without the help of the Chinook team (Jonathan Schaeffer, Martin Bryant, Robert Lake and Paul Lu), who not only gave me most of the information about Chinook that is contained in this article but also were kind enough to read the first draft of this article and offer useful comments. Andy Latto also gave me the benefit of his criticisms. Finally, Christopher Chabris and Jeremy Martin converted the text to HTML, caught many typos, and fixed many errors of fact. All remaining errors are, of course, my fault, and I will attempt to address all that are brought to my attention.

Readers interested in getting more (and more reliable) information about Chinook should not miss Jonathan Schaeffer's engaging account "One Jump Ahead: Challenging Human Supremacy in Checkers", published by Springer-Verlag in 1997.

This article is copyrighted by James Propp, 1997. Readers are free to transmit this article but not to modify it in any way without the author's express permission.