Computer Chess Club Archives




Subject: Re: Proving something is better

Author: Uri Blass

Date: 12:49:14 12/18/02

Go up one level in this thread

On December 18, 2002 at 15:43:56, Omid David Tabibi wrote:

>On December 18, 2002 at 14:31:21, Bruce Moreland wrote:
>>On December 18, 2002 at 11:29:37, Omid David Tabibi wrote:
>>>On December 18, 2002 at 11:23:38, Gian-Carlo Pascutto wrote:
>>>>On December 18, 2002 at 11:15:01, Omid David Tabibi wrote:
>>>>>I further don't understand why all the fire is directed at me; fixed depth
>>>>>comparisons are the common accepted comparison methods, which are completely
>>>>>hardware independant.
>>>>>For the most recent examples take a look at Heinz and Plaat's numerous >articles, all of which were conducted in fixed depth.
>>>>I would think that the best research is the one that improves upon
>>>>the mistakes of previous ones.
>>>I am yet to be convinced that the methodology practiced by Hyatt, Schaeffer,
>>>Marsland, Buro, Plaat, Heinz, and others, is mistake.
>>I have complaint with how this is applied, sometimes.
>>One type of test involves making the tree smaller, period, while doing the same
>>kinds of work.  If Schaeffer is going to test the history heuristic, that's
>>great -- if the tree is smaller, it's a win, because if you can consistently do
>>the *same* stuff in fewer nodes, that's always good.
>>The only possible criticism I can have of something like this is if it doesn't
>>use enough test positions.
>>If you are trying to prove that something sees more, what does seeing more mean?
>> You can blow the tree size up by extending everywhere, and you will see more in
>>a given depth.  But depth is not the proper measure, since a larger tree size
>>will also take more time to search.
>>If you want to "improve" a chess program in this manner, just incorporate a
>>two-ply search into your eval function.  You'll find stuff two plies sooner.
>>The only reason that your experiment shows that VR=3 is better than R=2 is that
>>the solution set was bigger *and* the node counts were smaller.  You can
>>*assume* from that that the times are also reduced.
>>You can't make these assumptions about R=3 as compared with VR=3.
>>And for that
>>matter, you can't make them about R=3 as compared with R=2, given the data you
>>Your data strongly implies that R=3 is better than R=2.  That is disturbing,
>>since your paper regards the superiority of R=2 over R=3 as axiomatic.
>I didn't intend to reinvent the cycle. It has already been shown elsewhere that
>std R=2 is superior to std R=3.

if std R=2 is superior to std R=3 for program X when  VR=3 is superior to std
R=2 for program Y then it does not prove superiority of  VR=3 to std R=3

I believe that R=2 is not superior to R=3 for Genesis and I remember that even
before the article you claimed that R=3 is better than R=2 for genesis at long
time control.


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