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

Author: Uri Blass

Date: 13:06:56 10/03/03

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On October 03, 2003 at 15:57:03, Uri Blass wrote:

>On October 03, 2003 at 15:36:22, Mridul Muralidharan wrote:
>
>>
>>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:
>>>
>>>>Hi,
>>>>
>>>>  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 -
>>>>nothingelse.
>>>>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.
>
>I already use them for that purpose.
>I did not say that hash tables are not used.
>
>
>
>>If you can afford to make these statements - then your impl is horribly full of
>>bugs.
>>
>>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 test also in games.
>>
>>
>>>>
>>>>
>>>>>(I have a lot
>>>>>of stuff that means that pruning or extension is not defined only by the
>>>>>position).
>>>>
>>>>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 ;)
>
>I test.
>
>>
>>>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
>>>better.
>>>
>>>There is a lot to improve and the main problem is programming.
>>>
>>>Uri
>>
>>
>>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 ? ;)
>
>code.
>
>I do not plan to use smp and I believe that the things that I mentioned can give
>a lot.
>
>>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 :)
>
>You misinterpt me.
>I did not decide that something is better based only on test positions.
>
>Uri

Note also that I looked at the source code of Crafty and learned somethings from
it and I also looked at the source of tscp and understood most of it before
writing movei.

Uri



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