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Subject: Re: Returning PV from hash table

Author: Nathan Thom

Date: 16:11:43 01/15/03

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On January 15, 2003 at 18:50:29, David Rasmussen wrote:

>On January 15, 2003 at 18:38:38, Nathan Thom wrote:
>
>>I just realised that my program LittleThought (in progress, hoping noone has yet
>>used this name?) only stores the best move in the hash table, so when a hash hit
>>occurs it cannot display the entire PV for that depth like everyone else's seems
>>to.
>>
>>Do you all store the entire PV in the hash entry? or some other trick im
>>missing?
>
>No one stores the pv, it takes to much space.
>
>In general, you can't always get the entire PV if you use hashing, and you do if
>you want a serious program.
>
>First of all, you can try to probe the hashtable for the position resulting from
>the best move at ply 0 (the root) then if you get a best move for this resulting
>position, this will be the next move of the pv and so forth. So you can probe
>the hashtable to get the whole pv. It's a little more complicated than this in
>practice, but you get the idea.
>
>Secondly, it helps to store the pv in the hashtable after each iteration.
>
>There are other tricks to try, too.
>
>/David

So, do you assume none of the entries have been overwritten, because at the end
of a search you update the hash table again just to make sure the best move is
there?



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