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Subject: Re: question about fixing the time management of movei

Author: Uri Blass

Date: 16:02:49 07/29/04

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On July 29, 2004 at 18:30:26, Sune Fischer wrote:

>On July 29, 2004 at 11:44:39, Robert Hyatt wrote:
>
>>"more complicated" != "more advanced".  I don't believe it is possible to
>>accurately forecast the time for the next iteration.  Which means when is it
>>appropriate to do that quick nullwindow search?
>
>I can't pridict when a check extension is wasted and when it is useful either, I
>can only say if it works better or worse on average.
>
>> And when you do it and it
>>returns way quicker than you expected, what do you do with the remaining time?
>>
>>There appear to be more problems this way than with what I currently do...
>
>Simple != Good

I agree and not agree.

I agree that simple does not have to be good but I also think that exactly the
same thing can be more simple if it is a good code and less simple if it is a
bad code.

For example it is possible to have in many places in the code some conditions
like:
if ((a-b)*p<=c) when a,b,p,c global varaibles and
a=The time now
b=time of starting the search
p=the expected brancing factor
c=time that is too big to start a new iteration.

In my case I had some significant names but they still did not do the code easy
to understand.


It is also possible to have some code
if (time_next_iteration_is_too_big())
when the functions time_next_iteration_is_too_big() is defined in time.cpp and
is using static varaibles that only that file knows.

I think that the second solution is more simple inspite of the fact that the
algorithm is the same and I am now working on modification in movei to do the
code more simple without changing the time management algorithm.


>
>(I can play that game too:)
>
>>>But you have not tested what I'm suggesting.
>>
>>I have definitely tested doing a fail-low search.  You can find references to
>>that back in 1978 which was when I finally dumped the idea of "don't start the
>>next iteration if I don't believe it can be finished..."
>
>Then why did it not work, which part failed, what is your analysis?
>
>>>
>>>>Your "assumption" is based on facts that have tons of contradictory evidence (IE
>>>>I _have_ done lots of testing and reported on it many times in various ways.)
>>>
>>>AFAIK it was a completely new spin on an old idea.
>>
>>There's nothing new about the null-window search at all.  As I said, in 1980
>>_every_ search I did started with a null-window search.  As did Belle's...
>
>Don't mix two experiments here, I'm not talking about starting every search with
>a nullwindow...

Note only that if you start some search with null move window it is not only a
change in time management.

I believe that it can be a good idea to do it but I am now interested only in
changes in time management so I do not plan to test it in the near future.

Uri



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