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

Author: Christophe Theron

Date: 20:08:25 10/03/03

Go up one level in this thread


On October 03, 2003 at 18:21:33, Uri Blass wrote:

>On October 03, 2003 at 17:34:56, Christophe Theron 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.
>>>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 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 ;)
>>>
>>>>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 ? ;)
>>>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 are talking without knowing Uri, obviously.
>>
>>You are also talking about commputer chess without really knowing, I fear.
>>
>>Uri has been talking with us about chess programs for a long time without
>>writing one. So at the begining he came with ideas that were not really
>>relevant, or not exactly to the point.
>>
>>What I like about Uri is that at some point instead of keeping talking about the
>>subject he has started to write his own chess program. I also know that he has a
>>very scientific, objective approach in what he does.
>>
>>So if I was you I would not give Uri beginners's advices like "test, test -
>>don't assume". Because as far as I know that's exactly what he is doing.
>>
>>I also believe that Uri is right in not trying to get too much inspiration from
>>other chess programs.
>>
>>I think you should refrain from giving lame advices to Uri and tell us instead
>>about your achievements as a chess programmer.
>>
>>
>>
>>    Christophe
>
>Thanks for the support.
>I believe that I did not implement most of the ideas that I had before writing a
>chess program.
>
>There are things that I did not try not because I believe that they are not
>productive but because they are not simple to implement and I prefer to think
>about implementing more simple things first.
>
>About testing I can say that in a lot of cases I am not sure if the program is
>better after a change that I accept but at least I am sure that it is not
>significantly worse.
>
>Uri



I'm confident Movei will reach a very good level. In any case I give you credits
for starting your work on a real chess program. The experience you gain from
this immediately puts you above those who have never tried but keep talking, or
in some cases allow themselves to criticize.



    Christophe



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