Computer Chess Club Archives




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

Author: Vincent Diepeveen

Date: 11:12:09 10/04/03

Go up one level in this thread

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:
>>>>  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 :)
>You are talking without knowing Uri, obviously.
>You are also talking about commputer chess without really knowing, I fear.

Ugh, latest Messchess hands down kicks Movei.

>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.

Lucky you didn't write that this hasn't changed yet :)

>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.

like playing without book, randomly making 1.h3 and claiming that this was ok, i
found that a funny one :)

>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 doubt it ;)

>I also believe that Uri is right in not trying to get too much inspiration from
>other chess programs.

Some thing tells me that certain assembly programmers are very well in debugging
other commercial programmers software ;)

>I think you should refrain from giving lame advices to Uri and tell us instead
>about your achievements as a chess programmer.
>    Christophe

In case you missed it, Messchess is way higher rated than movei.

However Mridul is from India, so in contradiction to you, can't afford going to
the world champs otherwise he would have.

Oh another thing. He knows more about parallel searching, multithreading and
linux kernels than you do Christophe :)

Without Mridul, the Diep would have had severe problems getting to work as well
as it works now at the different supercomputers. Especially that itanium2

No bookmaker is going to accept betting at which program works soon parallel
better, messchess or tiger :)

Considering that all the future cpu's, at least 80% of them are already dual or
more processors (in case you missed it but all >= 3Ghz P4s and all P4 Xeon MPs
and a lot of P4 Xeons are SMT), that means that soon Messchess is a more modern
program than Tiger :)

Best regards,

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