Computer Chess Club Archives




Subject: Re: Doesn't appear to work for me (full data)

Author: Uri Blass

Date: 03:26:16 11/21/02

Go up one level in this thread

On November 21, 2002 at 06:25:17, Uri Blass wrote:

>On November 21, 2002 at 04:52:13, Omid David Tabibi wrote:
>>On November 20, 2002 at 22:05:29, Robert Hyatt wrote:
>>>On November 20, 2002 at 16:55:41, Gian-Carlo Pascutto wrote:
>>>>Nullmove in Deep Sjeng uses an algorithm of my own, but I can
>>>>switch it back to other systems easily. I did so for running
>>>>a few tests.
>>>>I made a version which uses Heinz Adaptive Nullmove Pruning
>>>>and a version which uses your verification nullmove.
>>>This would seem to be a bit harder than at first glance.  They say that
>>>if the normal null-move search fails high, then do a D-1 regular search
>>>to verify that, but while in that verification search, no further
>>>verification searches are done, meaning that the normal null-move search
>>>fail-high is treated just like we do it today..
>>>I'm going to experiment with this myself, just for fun, but it seems that you
>>>need to pass some sort of flag down thru the search calls indicating that
>>>you are either below a verification-search node or not so that recursive
>>>verification searches are not done...
>>Exactly!! (finally someone read the article carefully)
>>See Figure 3 for detailed implementation (the flag you mentioned which is passed
>>down as a parameter for search(), is called 'verify' in the pseudo-code).
>>At first stage leave alone the zugzwang detection part (the piece of code at the
>>bottom of Figure 3). Due to instablilities, some programs might do a needless
>>re-search. First let the algorithm work fine in general, and then do the
>>zugwzang detection part.
>I let the algorithm to work without zugwzang detection and first results seems
>not to be good
>Some positions I get at the same depth and
>the only position so far in the gcp test suite that I got at smaller depth for
>tactical reasons is
>[D]5rk1/1r1qbnnp/R2p2p1/1p1Pp3/1Pp1P1N1/2P1B1NP/5QP1/5R1K w - - 0 1
>I am going to try it in 10 sedconds per move and get resulkts in half an hour.

should be seconds,results,position
I type too fast.


This page took 0.06 seconds to execute

Last modified: Thu, 07 Jul 11 08:48:38 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.