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Subject: Re: Fruit 2 and endgame play

Author: Dann Corbit

Date: 13:36:47 01/13/05

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On January 13, 2005 at 14:11:32, Dann Corbit wrote:

>On January 12, 2005 at 19:18:13, Uri Blass wrote:
>
>>On January 12, 2005 at 18:37:25, Dann Corbit wrote:
>>
>>>On January 12, 2005 at 18:27:11, Uri Blass wrote:
>>>
>>>>On January 12, 2005 at 14:26:59, Dann Corbit wrote:
>>>>
>>>>>On January 12, 2005 at 14:02:53, Mridul Muralidharan wrote:
>>>>>
>>>>>>On January 12, 2005 at 13:01:29, Drexel,Michael wrote:
>>>>>>
>>>>>>>On January 12, 2005 at 12:42:05, Anthony Cozzie wrote:
>>>>>>>
>>>>>>>>So let me see if I understand this conversation correctly.
>>>>>>>>
>>>>>>>>1. I state that the 6 man tables are worth 100 elo
>>>>>>>
>>>>>>>I thought you were joking, but obviously I was wrong.
>>>>>>>
>>>>>>
>>>>>>I have no quantitative way of accurately guessing this too - but "depends on
>>>>>>program" maynot be a wrong statement ?
>>>>>>And both are definitely agreeing that there is a non-trivial improvement in
>>>>>>performance - right ? Then why disagree for the sake of disagreeing !!!!
>>>>>>
>>>>>>
>>>>>>>>
>>>>>>>>2. You disagree, and state they are worth 50 elo
>>>>>>>>
>>>>>>>>3. You do this by pulling numbers out of your ***
>>>>>>>>
>>>>>>>>4.  Since the full 6-man set hasn't been generated, and the elo gain is almost
>>>>>>>>certainly different for different programs, we are both guessing.
>>>>>>>
>>>>>>>Yes, but in this case Uri's guess is much more educated.
>>>>>>
>>>>>>Hmm , I dont see how - just 'cos there was a "women" reference ? :)
>>>>>>Jokes apart - the point to be taken is - they could be a SIGNIFICANT improvement
>>>>>>: and would be the world of difference between a loss and a draw (or a draw and
>>>>>>a win).
>>>>>>Depends on how you eval , and what you do in your search (extensions and qsearch
>>>>>>/threat detection).
>>>>>>Ofcourse , if you have a junk endgame eval with quiet decent middle game eval -
>>>>>>your improvement can be much higher than what both of them quote !
>>>>>>
>>>>>>But are we not quibbling over nitty gritty details ?? 50 , 100 , 125 - what does
>>>>>>it matter : it would be a substantial improvement !!!
>>>>>
>>>>>In 20 years, we might be able to memory map the whole 6 man set.
>>>>>That would yield a stupendous Elo increase for endgames.
>>>>
>>>>in 20 years computers will be very fast.
>>>>
>>>>faster computer mean less blunders without tablebases and mean that tablebases
>>>>are less important.
>>>>
>>>>I suspect that if you wait 20 years more than 90% of the comp-comp games in the
>>>>high level will be drawn even without the 6 piece set and 6 piece set will have
>>>>smaller influence relative to the influence that it has today.
>>>
>>>If you memory map the tablebase files, there is almost zero cost for a probe.
>>>It may be worthwhile someday also to memory map 7 man bitbase files.  With a 64
>>>bit CPU, 18,446,744,073,709,551,616 is the address space (per CPU).
>>>
>>>An oracle that is 100% certain to have absolutely correct information and which
>>>has almost zero cost for the info lookup will be a superior solution.
>>>
>>>The addition of code to compute endgames will necessarily slow down evaluation
>>>and complicate the code base.
>>>
>>>If the average user had 16 GB Ram systems now (and even now such a system can be
>>>purchased for about $12,000) then the existing 5 man tablebase files could all
>>>be memory mapped.
>>>
>>>I predict that in this case, there will be a very large Elo boost, even for the
>>>5 man tables.  I base this upon the substantial Elo boost which has been
>>>measured for bitbase files, which provide inferior information to that of a
>>>tablebase.  The benefit of a bitbase file is that it can be held in memory much
>>>more easily.
>>
>>What evidence do you have for substantial Elo boost for bitbase files.
>>What time control is used?
>
>I have seen the results of several experiments (at least two of them on the
>Winboard forum were discussed) and also have done my own experiments.  I have
>not seen evidence of substantial gain for tablebase files, but there is clear
>evidence for bitbase files.
>
>You can easily perform your own experiments with patzer and yace.  You will see
>benefit at every time control.

I should mention that my bitbase experiments also had tablebase files activated.
 I do not know if this is important or not, and probably experiments should be
also run with bitbase files only.



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