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Subject: Re: Infinite PV's / hash extraction repetition problem

Author: Robert Hyatt

Date: 20:33:48 02/24/03

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On February 24, 2003 at 23:07:19, Dann Corbit wrote:

>On February 24, 2003 at 22:06:51, Robert Hyatt wrote:
>
>>On February 24, 2003 at 20:38:31, Sune Fischer wrote:
>>
>>>On February 24, 2003 at 20:23:07, Robert Hyatt wrote:
>>>
>>>>On February 24, 2003 at 20:17:05, Sune Fischer wrote:
>>>>
>>>>>Hey there.
>>>>>
>>>>>I've dumped the triangle PV and are extracting from hash now.
>>>>>I'm wondering if what's happening here is normal....
>>>>>
>>>>>Sometimes when it finds a repetition it seems to go in a loop creating
>>>>>infinitely long PV's. What is the right way to handle this, should I cut the PV
>>>>>after 1st or 2nd rep, or just let it go nuts?
>>>>
>>>>Think about it.  If you go thru one loop, you will go thru an infinite number.
>>>>:)
>>>
>>>Yeah thought that was reasonable, but I couldn't figure out if maybe the depths
>>>on the entries played a role here, but guess they don't.
>>>
>>>>Cut the PV at the _first_ repetition.  :)
>>>
>>>Okay, so do you print the first repeated move, as in
>>>1.Qa4+ Bd7 2.Qb3 Be6 3.Qa4+ or just
>>>1.Qa4+ Bd7 2.Qb3 Be6 ?
>>>
>>>>Or else find a way to do int pv[infinity].
>>>>
>>>>:)
>>>
>>>Hang on, I need a moment to reflect on that one.. :)
>>>
>>>-S.
>>
>>It's a matter of taste of course.  But I lop the thing off after making
>>and printing the move, and then noticing it is repeated.  That "closes"
>>the PV so that I can see what is happening.
>>
>>You have to do this if you print EGTB PVs as well, obviously.  Been there
>>and debugged that problem too.  :)
>
>How about showing the 3-fold repetition?  Obviously, there is no need to repeat
>past that point.


Note that we are talking about a _loop_ in the actual PV shown.  Once you see
the second repeat, it is over, as you can then just duplicate what you have
displayed so far, as many times as you want.  :)

This isn't an issue so much about the game history, just about closing the
loop in the PV being displayed...

Displaying to the 3rd rep would be ok, but definitely redundant since the same
series of moves would be displayed two times, which would make the program a
bit "noisy"..



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