http://www.gothicchess.com/checkers.html
The new book files are here, plus a description of the previous unexplained "learning" function in WCC. Gil and I devised a way to make WCC stronger without having to recompile and redistribute a new program. If you update the "learning" file, new knowledge will be available to WCC as it searches.
Somehow, Gil forgot to include my "learning" book in the first release, so nobody has ever run WCC with this important new knowledge!
All versions of the program should play much better with this file installed. See the web page for more information.
WCC Download page
WCC Download page
--Ed