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Subject: Re: developing Junior (and other pro programs)

Author: Robert Hyatt

Date: 20:47:17 09/01/02

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On September 01, 2002 at 13:44:45, Gian-Carlo Pascutto wrote:

>On September 01, 2002 at 13:26:44, Robert Hyatt wrote:
>
>
>>>pawn=32 in fritz seemingly. that's all you need to know to consider
>>>it works for it.
>>
>>What does that do?  I have seen large positional scores out of fritz,
>>which suggests (to me) that mtd(f) could cause some problems...
>
>That means that Fritz has a low evaluation granulatiry, which keeps the
>number of MTD passes to a minimum. There's some disagreement here between
>Vincent and the rest of the world exactly how much this matters, but it
>does matter for sure.
>
>Positional scores have nothing to do with this, I don't know where you
>got that.
>
>--
>GCP

I have no idea what you are talking about above.  The problem that mtd(f)
encounters is with an eval that fluctuates significantly iteration to iteration.
That fluctuation is _not_ an issue of pawn values.  It is an issue of
positional scores.  You could have pawn = 10000 if your positional scores
don't vary much.  But if they vary by more than a pawn, you will have trouble
no matter what...

reducing the score range by a factor of 3 will help _some_.  But only _some_.

But when a program can produce scores with the positional component well over
two pawns, I don't think the actual pawn value has much effect on how mtd(f)
performs...  the constantly shifting eval is going to cause lots of re-searches,
from experience.,..



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