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Subject: Re: a question to Tord about detecting threats in null move

Author: Mridul Muralidharan

Date: 12:36:22 10/03/03

Go up one level in this thread

You misinterpreted me.

On October 03, 2003 at 14:51:24, Uri Blass wrote:

>On October 03, 2003 at 13:38:54, Mridul Muralidharan wrote:
>>  I was a bit taken aback by these declarations :
>>On October 03, 2003 at 12:47:23, Uri Blass wrote:
>>>I prefer even not to care about using hash tables for pruning because my
>>>experience told me that I cannot get significant gain there easily
>>Hash table not giving you pruning ? I suspect a bug in your hashkey -
>>Or maybe it is the easily that is operative word ?
>>I think there are a lot of open source programs that you can refer to and
>>correct your bugs with - crafty , GNUChess , etc , etc.
>>Might help to get this right.
>I do not like to copy from other sources.
>I found that instability helped me to do my program significantly better.
>If I delete it in order to be able to copy from other programs then I may need
>to start by doing it significantly weaker.

I did not mean - "copy" here.
Rome was not built in a day. What I meant is :
Look at their implementation - check yours. Find any obvious bugs.
I seriously suspect that there are - since hashtables not only help in pruning ,
but massively help in move ordering.
If you can afford to make these statements - then your impl is horribly full of

As far as "instability helping" - I'm really not sure what you mean by this. As
far as I know - everyone , including me , tries to reduce instability so that
search is more stable requiring minimal search tree.
Wild extensions , unstable pruning , etc may help you in solving test suites
better and faster - but in real world games , it will suck badly.

>>>(I have a lot
>>>of stuff that means that pruning or extension is not defined only by the
>>Where ever possible , I try to make the search behaviour as relevent to the
>>current position as possible and not rely on past search.
>>Why do you want to do the opposite ?
>because the opposite gives me some advantages.

test , test , test - dont assume.
like my collegue says : When you AssUMe , you make an Ass of U and Me ;)

>Movei has its chances against every program inspite of having bad order of moves
>and bad extensions and bad pruning.

acceptance is the first step to improvement !

>I believe that I can get above Crafty level if I improve order of move
>extensions,pruning and evaluation.
>Movei already has its chances against Crafty but today crafty is significantly
>There is a lot to improve and the main problem is programming.

AFAIK movei is not smp - so no point in saying search here :)
SO , other than move ordering , eval and pruning : what else is left ? interface
code ? ;)
anyone can get to crafty level or higher - IF you are willing to put in the
effort and scientifically research.
All the best - wishing to see a better Movei and a more scientific Uri :)

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