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Subject: Re: not using nullmove?

Author: Uri Blass

Date: 07:03:22 02/15/04

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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.


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