Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Any programs besides Yace and Patzer that can use bitbase files

Author: Dann Corbit

Date: 18:05:21 06/17/04

Go up one level in this thread


On June 17, 2004 at 19:32:17, Dieter Buerssner wrote:

>If anybody wants to implement "bitbases", and really doesn't want to do it more
>or less with own ideas, the articles of Ernst Heinz show really everything
>needed. After that, it should only be a programming exercize. The articles are
>avialable at http://supertech.lcs.mit.edu/~heinz/node17.html
>
>Especially interesting in this context:
>
>Space-efficient indexing of chess endgame tables.
>Knowledgeable encoding and querying of endgame databases.
>Endgame databases and efficient index schemes.
>Efficient interior-node recognition.

Yes, I have those papers.

>But with knowledge of the basic ideas, who to use symmetry to index
>TB-positions, many people will be able to come up with similar ideas, that
>should also work well (and perhaps identically). It might be more fun.

I sometimes wonder if there is a fundamentally better way to compress.  I have
thought about a minimal perfect hash for every legal move on a sparse board.  We
could encode it in a minimum number of bits, amounting to the number of possible
total moves for a set (as reduced by reflections, rotations, etc).

Of course, you would have to compute a new hash for each new set.

The reason I brought it up was that I think it would be nice if there were a
standard way to do it.  Imagine if every chess program author made his own
tablebase files.  Sounds like a clever thing that would encourage innovation.
That's on the one hand.  On the other hand, there would be 250+ redundant 7 gig
file sets on my computer.  That would be a bit annoying.



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.