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Subject: Hash hit ratios

Author: Rick Bischoff

Date: 16:15:58 09/29/04


Hello,

I use an aging counter in my hash table, that is incremented after each "real
game move"-- anyway, Do these stats look "normal" for you regarding hash hits,
etc?

A hash hit: keys match (thereby giving a good move to try)

The rest of the scores below mean that there was a hash hit and that the stored
depth >= current search depth:

exact: stored age == age and flag == exact
upper: flag = alpha with no referenece to age
lower: flag = beta with no reference to age

I did the whole invalidating exact aging scheme because my program kept on
getting into "hash loops" in certain positions where it would keep on playing
the same line over and over again, thereby converting a won game into a draw.

I replace always EXCEPT where the search has the same age and less than equal
depth to the stored entry.

***** 11201 ms elapsed 1247030 nodes 111332 nps.  181809 probes %13.6242 hits,
%0.0440022 exact, %2.67203 lower, %1.0577 upper. nulltry=127769 nullsec=84970
ext:(mate=63,check=29699,pawn=143)



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