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Subject: Re: Hash Table Collisions

Author: Tom Kerrigan

Date: 09:19:45 04/13/00

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On April 13, 2000 at 11:11:24, KarinsDad wrote:

>On April 12, 2000 at 22:59:22, Tom Kerrigan wrote:
>
>>In my experience, here's what happens:
>>
>>You search the initial position to 10 ply and play e4.
>>
>>Because of that search, there is a "9 ply" hash table entry for the resulting
>>position.
>>
>>So when you start the next search, you do a 1 ply search(). It finds the hash
>>table entry, sees that 9 > 1, and returns immediately. Then you do a 2 ply
>>search(), same thing happens. Until you do a 9 ply search.
>>
>>So it's not necessary to keep track of which entries are still "good" because
>>you start the search up again where you left off.
>>
>>-Tom
>
>Ok, maybe I am just confused here. I thought that if you found an entry in the
>"9 ply" portion while searching the 10 ply off the initial position, that entry
>may or may not get overwritten due to a hash table collision (hence, the need
>for the counter).

Now I'm confused. :)  Are you talking about doing a search A and during that
search, it overwrites a hash entry made by the same search (A)?

-Tom



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