Author: Koundinya Veluri
Date: 09:45:35 12/02/01
Go up one level in this thread
On December 02, 2001 at 12:16:57, David Rasmussen wrote: >Where can I find some good huge pgn files or collection of pgn files for opening >book creation? I have gotten the 2600u.zip file from Dann Corbits site, but with >a threshold of 5 games, to a depth of 60 plies and a win percentage of 50, it >yields only a relatively small opening book of less than 16000 positions. How >many positions does tournament opening books for professional programs usually >contain? I know that automatic opening book creation is a science in itself, and >a design choice for the engine as such, but still, I have the impression that >people that _do_ use automatically generated opening books have much larger >books that 16000 positions. > >/David Hi David, A threshold of 5 games might be too big for the 2600u collection because it has already been cleaned several times. 1 worked well for me, even 2 removed too many variations from the book, but all depends on how the program chooses which positions to store of course. But if the program has a good algorithm for picking book moves, then a threshold of 1 should do. I created one from 2600 for my program (although it doesn't have win percentage yet) with a threshold of 1 game to 60 plies. It has about 1.2 M positions and rarely comes out of book with an obviously lost position. Also, if you use a threshold of 1 game, you might also want to reduce the ply count to 30 or 40. You can also try Enormous.pgn from the Crafty FTP site if you really want a near-1GB pgn file, but there are many sizes of pgn collections there. For the enormous, a threshold of anywhere from 2 games to 5 games works well for me. Crafty FTP: ftp://ftp.cis.uab.edu/pub/hyatt/ Look in the common folder. Regards, Koundinya
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.