2004 Opening Book Skeleton


You can download here a set of 143396 games (around 80000 without transpositions) in the Wthor format, a widely used format to store Othello game databases, and another set of 460859 games (around 240000 without transpositions).

Those games are the best part of two successive versions of edax's book. All of them lead to a draw and Edax 4.0, at the date of the book knew no way to refute them. Edax spent about 6 years × Ghz to built them, trying to expand the most promising lines. The resulting books are rather wide and contains respectively about 6.5 million positions and 9.7 million positions. The first one has been evaluated at 18 ply deep in midgame, 27 ply deep in selective endgame, and solved for the last 21 moves ; the other one at 19 ply deep in midgame, 30 ply deep in selective endgame and solved for the last 24 moves. Unfortunately this is probably still not deep enough and edax's book surely contains many blunders. Nevertheless, I hope this book can be usefull for bots or people who want to study openings.

These sets of games contain all deviations up to 21 empties starting by the move F5, except the trivial transposition F5D6C3D3C4 of F5D6C4D3C3 and the opening F5F6E6D6 symetrical of F5F6E6F4. All other deviations have been kept. Since Edax 4.0 was in development and not always stable, it is highly possible that some lines are flawed; but I hope this number to be low.

book extractedax-pvbook-2008-10-23.wtb.zip
book extractedax-pvbook-2008-11-01.wtb.zip


This set of games is in the public domain.