Author: Tony Werten
Date: 01:39:43 08/17/03
Go up one level in this thread
On August 16, 2003 at 23:14:45, Robert Hyatt wrote: >On August 16, 2003 at 07:23:49, Gian-Carlo Pascutto wrote: > >>On August 15, 2003 at 22:56:34, Robert Hyatt wrote: >> >>>On August 14, 2003 at 15:27:06, Peter Fendrich wrote: >>> >>>>1FH = The ratio where the first generated move in the node is a Fail High. >>>> >>>>I experimented with removing the the hash table and became a bit surprised. >>>>Normally I have about 1FH = 95-96%. When I removed the hash table that figure >>>>raised to more like 1FH = 96-97% while the search depth, as expected, was >>>>decreased. >>>> >>>>Increased 1FH when removing the hash table. Is this normal? >>> >>>Probably. You increased the size of the tree. And for the extra stuff you >>>searched, you searched it pretty accurately. But you _did_ search it, which >>>slowed you down. :) >> >>No! - That does not make any sense at all. > >Sorry, but it makes _lots_ of sense. > >If you don't try a hash table move first, then you will probably try captures >and captures have re-captures that work instantly. Hence more cutoffs. Just >try it... > >The hash move is often _not_ a capture. But if you try a capture first, >then the corresponding re-capture will be an instant cutoff that is easier >to find than a reply to a non-capture. > >> >>"the extra stuff you searched, you searched it pretty accurately" >> >>If we disabled hashing and hence handicap move ordering, we'll do >>worse, not better, on average. >> >>Yes, we may generate extra nodes and do well there, but that's certainly >>not what we should expected in the average case, since we just made >>our move ordering worse! >> >>Do you see your contradiction? > >Not at all. See above. Which is easier to refute, a non-capture or a >capture? > >Answer: A capture. This is incorrect. It will be the opposite most of the time. Place a queen on the board, count the amount of bad captures it can make, now count the amount of squares it can go to that are defended ( and the queen will be captured) I'm pretty sure the latter will be higher most of the time. Maybe you meant: Is a move easier refuted by a capture or a noncapture ? Tony > >> >>-- >>GCP
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