Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Questions about Nimzo8 and its proprietary endgame tablebases.

Author: Ernst A. Heinz

Date: 12:12:52 12/22/00

Go up one level in this thread


Hi Peter,

>These are meant to be permanently stored in RAM, and thus the significant RAM
>requirement. At the same time Nimzo8 still uses Nalimov tablebases and assigns
>RAM for that.
>
>1. Isn't there an overhead of trying to use both?
>2. What is a reasonable strategy for allowing Nizmo8 to use one vs. the other?
>I.e. should a nominal amount of RAM be assigned for caching Nalimov tablebases
>and the rest (as much as possible) to Nimzo's own?
>3. Finally, does it make sense to increase these allocations at the expense of
>the main hash table size?

Chrilly Donninger's RAM-based endgame databases are based on a
technique first used in our chess program "DarkThought" during
the 15th WMCC in 1997. I named them "knowledgeable endgame
databases" because they employ domain-specific a-priori knowledge
to reduce the amount of information stored per position to just
a _single_ bit in many cases. This is only half the space that
would be required for vanilla W/D/L = win/draw/loss databases
using 2 bits for the three W/D/L values per position.

The RAM-Based knowledgeable endgame databses of "DarkThought"
consume less than 16MB of RAM for the full set of all 3- and
4-piece endgames. AFAIK, Chrilly has added some more databases
while compressing them on top of the knowledgeable encoding
scheme with a standard compression technique.

According to my own experiences with "DarkThought", RAM-based
knowledgeable endgame databases are certainly worthwhile every
bit of RAM they consume. Hence, I always load them if possible.

Please point your browser to the WWW pages of "DarkThought" at
http://supertech.lcs.mit.edu/~heinz/dt/ to find out more about
our RAM-based knowledgeable endgame databases.

=Ernst=





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.