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Subject: Re: Adjusting Alpha / Beta based on Hash table entry?!?

Author: Tony Werten

Date: 02:09:18 03/19/02

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On March 19, 2002 at 05:04:15, Tony Werten wrote:

>On March 19, 2002 at 04:34:28, Steve Maughan wrote:
>
>>Ulrich & Tony
>>
>>>>This means your bestmove will "fail low", and not get recorded as bestmove.
>>
>>As Ulrich states this isn't really a problem as you just retirn 100 (in your
>>example) and the PV stops at this node.  The issue that I think you may be
>>alluding to is that when this move is then stored in the hash table there will
>>not be a move associated with it as it's a fail low - but there will be from the
>>previous search.
>
>Wow ! Does this mean that when you enter a node with a bestmove from hashtable
>and this node fails low, you keep the best move ?

Sorry my mistake. You mean the entry will not be overwritten since the old one
has a bigger draft.

Hmm, seems to indicate I was talking complete crap. So where do those short pv's
come from ? I'll think a bit about it while doing some work.

Tony

>
>Not a good idea.
>
>Tony
>
>>
>>I've played around with it and the result is that one sometimes gets annoyingly
>>short PVs.  I still don't like the idea of lowering beta.  I'll tinker some
>>more,
>>
>>Thanks,
>>
>>Steve



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