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Subject: Re: Eureka! Voila! Ooh La La! (Thanks Uri!)

Author: Uri Blass

Date: 03:35:35 12/04/05

Go up one level in this thread


On December 04, 2005 at 06:11:47, Reinhard Scharnagl wrote:

>On December 04, 2005 at 06:00:30, Uri Blass wrote:
>
>>On December 04, 2005 at 05:32:13, Reinhard Scharnagl wrote:
>>
>>>On December 04, 2005 at 05:25:43, Uri Blass wrote:
>>>
>>>>On December 03, 2005 at 23:39:19, chandler yergin wrote:
>>>>
>>>>>All expressions of great Joy.
>>>>>"Eureka cried the ancient Philosopher! The religious have an Epiphany!
>>>>>I just had another Beer.. and it came to me!
>>>>>I finally understand.. (I think) what you guys are doing, and want to do better.
>>>>>(If I don't I'm sure you'll tell me.
>>>>>;)
>>>>>You need a way to Test your Engines; and Tweak them and have irrefutable
>>>>>evidence of performance. In other words, a "Benchmark"; a Baseline for
>>>>>comparison purposes.
>>>>>Most of you use Test Positions! The problem there is, that every Engine will
>>>>>evaluate a poition differently.
>>>>>What is the one thing in Chess that will never change?
>>>>>What is the one Constant that will never change?
>>>>>
>>>>>The number of "possible" moves at various Ply Levels!
>>>>>Here they are:
>>>>>
>>>>> 0  1
>>>>>ply 1 20
>>>>>ply 2 400
>>>>>ply 3 8890
>>>>>ply 4 196812
>>>>>ply 5 4838258
>>>>>ply 6 118251225
>>>>>ply 7 3162798012
>>>>>ply 8 84029997363
>>>>>ply 9 2403434332264
>>>>>ply 10 68265214423776
>>>>>ply 11 2058141026024096
>>>>
>>>>correct numbers can be productive for programmers to check bugs but
>>>>your numbers are not correct
>>>>
>>>>
>>>>A table of perft results for the start position:
>>>>1 20
>>>>2 400
>>>>3 8,902
>>>>4 197,281
>>>>5 4,865,609
>>>>6 119,060,324
>>>>7 3,195,901,860
>>>>8 84,998,978,956
>>>>9 2,439,530,234,167
>>>>10 69,352,859,712,417
>>>>
>>>>Source
>>>>
>>>>http://homepages.caverock.net.nz/~peter/perft.htm
>>>>
>>>>Note that I do not plan to respond to every post that I disagree with you and it
>>>>is a waste of time if you try to teach people in subjects that they know more
>>>>than you.
>>>
>>>Hi Uri,
>>>
>>>those seems to be numbers of DIFFERENT POSITIONS not of POSSIBLE MOVES.
>>>
>>>Reinhard.
>>
>>Hi Reinhard,
>>
>>I do not know what chandler yergin means by possible moves but his first 3
>>numbers are exactly the number of different games of 0 ply,1 ply,2 ply.
>>
>>The perft numbers are not numbers of different positions but number of possible
>>games.
>>
>>1.e4 e6 2.d4 and 1.d4 e6 2.e4 lead to exactly the same position and there are
>>many examples so the number that I gave for 3 plies is not the number of
>>possible positions after 3 plies but the number of possible games with 3 plies.
>>
>>Uri
>
>Hi Uri,
>
>have a look at http://www.cs.berkeley.edu/~flab/chess/statistics-games.html
>
>Reinhard.

Thanks

This explain the numbers in the original post.
Note that I do not understand what is double discovered check.

I do not know about double checks when a piece that moved does not give check.

I can think about promotion but even in the diagram that I give axb8=R+ is a
check by the pawn that moved and became a rook so it is double check by a piece
that moved.

[D]kr6/P7/R7/8/8/8/8/K7 w - - 0 1

Uri



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