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Subject: Re: Fruit: first observations. Not a coconut yet, a budding pomegranate

Author: Uri Blass

Date: 23:04:31 03/11/04

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On March 11, 2004 at 12:56:01, Robert Hyatt wrote:

>On March 11, 2004 at 05:56:40, Uri Blass wrote:
>
>>On March 11, 2004 at 05:21:03, Fabien Letouzey wrote:
>>
>>>
>>>On March 10, 2004 at 22:39:48, Djordje Vidanovic wrote:
>>>
>>>>Fruit is a very nice new program that can be freely downloaded from Dann
>>>>Corbit's ftp site.  It is a UCI engine and can run either under Arena or the CB
>>>>GUI.  I tried it in a very short match (played at quick blitz controls) against
>>>>one of the older Crafties (18.12) and it did not have much of a real chance to
>>>>score.  It does seem to be very promising though as it had a couple of playable
>>>>and perhaps winnable positions, but due to the apparent lack of knowledge it
>>>>lost even these games.  I think that game 4 could be very telling for the
>>>>programmer who said that he was a little disappointed with CCC.  Ahem, he should
>>>>know that all things that matter in life usually take time, and CCC is just like
>>>>that especially at the beginning. He will surely be overwhelmed eventually with
>>>>the amount of feedback by CCC members.
>>>
>>>Fruit is of course not in the same league as Crafty.
>>>
>>>The lack of knowledge is real, not apparent :)))
>>
>>The lack of knowledge in crafty is also real.
>>Crafty does not know things like ETC.
>
>ETC is _not_ "knowledge".  It is a modification to move ordering only.  If you
>look at comments in main.c, I tried ETC more than once.  I reported here that it
>was worse for Crafty, as it is a speed slow-down, and the goal is for the speed
>cost to be offset by less work due to a quicker hash cutoff.  It was _slower_
>for me, so the fact it is not in is not an oversight, it is a design choice.
>
>It might work fine for you, but it was worse for me and I got rid of it...

I understand but I try to explain what is the reason that fruit get good
results inspite of having almost no evaluation(it has only piece square table
and few boolean features and has for example no king safety evaluation and no
endgame knowledge)

The fact that based on the results that I read if you add to fruit book it seems
to be only something like 100 elo weaker than Crafty is surprising and suggest
that something should be improved in the search of Crafty.

Maybe you need to do other changes in the search before ETC works for you(for
examples checks in the first ply of the qsearch and changing that are done by
fruit and changing R=2/3 to R=3 after having checks in the first ply of the
qsearch).

Uri



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