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Subject: Re: SEE for forward pruning in Q. Search

Author: Dave Gomboc

Date: 21:17:27 08/10/99

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On August 10, 1999 at 21:55:29, Robert Hyatt wrote:

>On August 10, 1999 at 18:42:58, Tom King wrote:
>
>>On August 09, 1999 at 20:41:50, Robert Hyatt wrote:
>>
>>>On August 09, 1999 at 17:51:01, Tom King wrote:
>>>
>>>>On August 08, 1999 at 21:35:46, Robert Hyatt wrote:
>>>>
>>>>[snip]
>>>>>
>>>>>
>>>>>I've been doing a 'hybrid' for nearly a year...  R=3 fairly close to the
>>>>>root, R=2 beyond some threshold that I don't remember what it is...
>>>>>
>>>>>
>>>>
>>>>Interesting.. better than pure R=2 or pure R=3? I did some experiments a while
>>>>back, using R=3 on the opponent's move, and R=2 on the computers move (idea
>>>>being - let's not cover up the opponent's threats, and if we miss some of our
>>>>threats, well, so be it). But it was more or less a 'wash'.
>>>
>>>
>>>I started playing with this after Paris, as someone said that Frans (or someone)
>>>was fiddling around with R=3.  Bruce and I played a few games one night with
>>>Ferret vs Crafty, with bruce using R=3, and we saw _no_ gross mistakes on his
>>>part.  In fact, we couldn't tell the difference (at least R=3 was not making
>>>mistakes that R=2 wasn't).
>>>
>>>But I never felt comfortable with raw R=3, as R=2 causes more than enough
>>>problems already, thank you very much.  :)
>>>
>>>Ernst is writting an ICCA paper describing some experiments he did with this
>>>(totally unconnected with my tests).  Wait for his paper to hit the journal as
>>>he has some good data...  And I am not yet sure that this is a good idea, but I
>>>have been running it a good while and it has been in the distributed Crafty for
>>>quite a while as well and no one has complained.  Of course, now that everyone
>>>knows, look out.  :)
>>
>>One thing's for sure - I'm sure there's a lot more we could all be doing with
>>the null move. Playing around with different values of R, depending on depth in
>>the tree, alpha and beta etc. etc. I look forward to this paper. Ernst has been
>>productive of late..I'm sure I'm not the only one to enjoy reading his articles.
>>[even if his damn program does kill mine at the WCCC ;-)]
>>
>>Cheers,
>>Tom.
>
>
>If you want to play around, here's another idea I have on my 'to-do' list:
>
>at present I 'break' the search into two 'chunks'.  the part near the root
>uses R=3, the rest uses R=2. Something tells me this might be made much more
>dynamic than that...  ie R=4, then 3, and finally 2.  But rather than some
>static divisor as I have now, make this dynamic so as you go deeper, you use
>bigger R values near the root, etc...
>
>Seems reasonable.  Whether it will work or not, we won't know until we try
>it...

What relationship, if any, would you posit between a good R and how sharp or
quiet a position is?

Dave



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