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Subject: Re: not using nullmove?

Author: Christophe Theron

Date: 10:19:38 02/15/04

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On February 15, 2004 at 10:03:22, Uri Blass wrote:

>On February 15, 2004 at 08:53:42, martin fierz wrote:
>>On February 14, 2004 at 13:16:15, Christophe Theron wrote:
>>>What I have always tried to do is to hide the details of what's inside Chess
>>>Tiger (in order to protect my work a little bit) but still explain what my
>>>methodology (or work philosophy) was (in order to somehow give back to the
>>>I think it's important to have strong guidelines in your work. Some of them come
>>>from your knowledge of information processing in general (be careful not to
>>>create bugs, don't waste resources, never trust Microsoft...), and some of them
>>>are specific to the domain of chess programming and took me years to figure out.
>>>For example:
>>>* don't compute something in advance if you are not sure you will use it,
>>>because chances are that you will get a cutoff before you need it (remember it's
>>>just a guideline - sometimes you can break this rule).
>>>* you need a very accurate way of measuring progress, or you will not make
>>>progress at all.
>>>* Any change can make your program significantly weaker. You need to test your
>>>changes (with the method you have built) very often.
>>>* People believe that chess is about evaluation, but actually it's all about
>>>search (I'm trying very hard to break this rule, because it must be wrong from a
>>>mathematical point of view, but it's really difficult).
>>i'm not sure i agree with this one - but then i don't quite know what you mean
>>with that sentence :-)
>>my disagreement comes from the fact that improving your eval automatically
>>improves your search when you use any kind of pruning which depends on the
>>evaluation. nullmove is such an example, but this is a general observation which
>>works for other kinds of pruning decisions like futility pruning too. if you
>>evaluate better, you have a greater chance of searching/extending important
>>lines and pruning the irrelevant lines.
>>but perhaps you meant something different?!
>>  martin
>I think that christophe meant that based on his experience changes in search
>rules gave him bigger improvement than changes in evaluation.

It's based on my experience and the opinion of other people as well (including
chess players).


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