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Subject: Re: Combining Internal Iterative Deepening, History and Killers

Author: Robert Hyatt

Date: 20:08:07 07/06/01

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On July 06, 2001 at 14:27:39, Artem Pyatakov wrote:

>I was taking a peek at Crafty's source code and came across this comment inside
>the Search() function:
>----------------------------------------------------------
>|                                                          |
>|   if there is no best move from the hash table, and this |
>|   is a PV node, then we need a good move to search       |
>|   first.  while killers and history moves are good, they |
>|   are not "good enough".  the simplest action is to try  |
>|   a shallow search (depth-2) to get a move.  note that   |
>|   when we call Search() with depth-2, it, too, will      |
>|   not have a hash move, and will therefore recursively   |
>|   continue this process, hence the name "internal        |
>|   iterative deepening."                                  |
>|                                                          |
> ----------------------------------------------------------
>
>The comment makes complete sense and "Internal Iterative Deepening" sounds like
>a great idea, but could somebody  please explain to me how to integrate this
>algorithm with the Killer and/or History heuristics? Thanks in advance.


Simple.  If this is a PV node, use IID.  If it is not a PV node, then use
the normal history/killer stuff as that is good enough.  But on the PV, you
are searching one ply deeper, and the history/killer stuff is not as accurate.



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