Author: Robert Hyatt
Date: 18:57:25 07/20/02
Go up one level in this thread
On July 20, 2002 at 02:39:45, Uri Blass wrote: >On July 19, 2002 at 19:59:26, Robert Hyatt wrote: > >>On July 19, 2002 at 13:45:07, Uri Blass wrote: >> >>>On July 19, 2002 at 13:16:06, Joshua Lee wrote: >>> >>>>I was wondering that if the DB team estimated a rating or over 300 points higher >>>>than the programs at that time on equivalent hardware or equal search, they >>>>weren't clear on that. That would mean 2796 on a P200 and Fritz 7 for example >>>>wouldn't be anywhere near this on a P200. Has anyone seen anything about their >>>>tests against commercial software and does anyone have any opinions about this? >>>> >>>>Granted that Software has improved and that on Todays Fastest Hardware The Top >>>>Programs (provided the SSDF list is that accurate) is on equal footing with Deep >>>>Thought and DB Jr. >>> >>> >>>Why do you think that they may be only equal. >>>I believe that the opinion of most programmers is that >>>the top programs of today are clearly better >>>than Deep thought and deep blue JR. >>> >>>It is known that their search algorithms were bad >>>relative to what is known today >>>(otherwise you could see people who copy their >>>search algorithms with good results when I know that >>>the people who tried to copy the way that they use >>>singular extensions got bad results in games so >>>they do not use it). >>> >>>It is known that they believed some wrong assumptions >>> >>>They believed that null move pruning is dangerous at >>>their speed when the results say that null move pruning >>>is only more productive when the machines are faster. >>> >>>They believed that the brute force depth is not very important >>>at their speed and singular extensions are more important >>>and they were again wrong(programs already >>>have similiar speed to deep thought and they do not use >>>singular extensions in the way that deep thought used them). >>> >>>Their speed simply misleaded them to wrong assumptions >>>that they did not test. >>> >>>Uri >> >> >>That last sentence is simply wrong. >> >>On two counts... >> >>1. They tested _and_ wrote several papers on their search extensions. It >>was hardly "not tested". > >I assume for this discussion that they tested it in games against >a version without null move pruning and without singular extensions. > >Did they test it in games against a version with null move pruning? Why does it matter. You can focus (a) on selective extensions (b) selective forward pruning (c) both All three, if done properly, will produce _identical_ results. > >It is possible that they could get 2 productive changes: > >1)Add null move pruning >2)Not use the singular extensions. Why make such an assumption when several are using or testing singular extensions? It obviously seems to work. > >It is possible that 2 is not productive without 1 and >if they did not start by testing 2, they got the wrong conclusions. > >Did somebody try to test crafty with their algorithm >(no null move pruning and singular extensions)? Not that I am aware of... > >I guess that it is going to be clearly weaker than >the Crafty of today at 120/40 time control. > >Uri If SE is all you test, probably it will be weaker. But SE is _not_ all the DB guys did for extensions. They had many others as well...
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