Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: About qsearch...

Author: Uri Blass

Date: 01:10:28 12/30/01

Go up one level in this thread


On December 30, 2001 at 03:56:36, Severi Salminen wrote:

>>Here are the results of my program when searching depth 7 from the initial
>>position:
>>limit of qsearch in plies is the first number in every line   and  nodes for
>>depth 7 is the second number:
>
>>I think that limiting the qsearch too much may do chess program slower in
>>getting the same depth thanks to bad order of moves
>
>(Limiting) qsearch should not have anything to do with move ordering. Ordering
>is usually statical and takes place in every node, or then you are doing
>something very interesting.

The pv is dependent on the depth qsearch and starting from the pv is not
something very interesting.

The history table is also dependent on the qsearch and if the qsearch is limited
there is a bigger chance that the history table is going to be wrong.

Both history table and starting from the pv is used by tscp.

>
>>0   2868842
>>1   3611982
>>2   997968
>>3   1564826
>>4   1196247
>>5   1214999
>>6   1184129
>>7   1153555
>>8   1180282
>>9   1153618
>>=10  1153584
>
>I don't quite understand the numbers (they include _all_ the nodes, right?)
>above. 0 means actually a 7 ply search with no qsearch at all? 1 means 7 plies
>of full width and 1 ply qsearch? How can 2 ply limit have only 997968 nodes?
>Shouldn't the number increase when increasing the limit? I'm missing now
>something important...
>
>Severi

It seems to be a question of luck
The program sometimes change it's mind more often or less often but my
impression is that limiting the qsearch does not reduce the number of nodes in
general.

Uri



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.