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Subject: Re: OT: Re: Mathematical impossibilities ..

Author: Andrew Dados

Date: 15:55:41 01/30/02

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On January 30, 2002 at 18:47:11, Dann Corbit wrote:

>On January 30, 2002 at 18:11:27, Tony Werten wrote:
>
>>On January 30, 2002 at 11:56:39, Thomas Mayer wrote:
>>
>>>Hi Peter,
>>>
>>>>>4^17= 2*(2^17)= 2^18
>>>>
>>>>ROTFL - this thread is definitely getting entertaining :-)
>>>>
>>>>4^17 = (2*2)^17 != 2* (2^17)
>>>
>>>seems that some forget here simple mathematical rules... :) Anyway, I wonder
>>>what this thread is good for... IMHO Deep Blue is something mystical, we can't
>>>catch it anymore... The efforts of the Deep Blue Team were definitely remarkable
>>>to whatever depth it has searched.
>>
>>Agreed. They were the first to beat the world champion (nobody is going to beat
>>that). They searched a remarkable depth ( with their approach even for today but
>>specially for 10 years ago ). But they did _not_ search 18 ply.
>
>4^17 is 17,179,869,184 (17 seconds at peak, and 85 seconds at 200M NPS)
>
>4 times longer would be 340 seconds.  About five and a half minutes.
>
>Let's see...
>40 moves in 2 hours is 40 moves in 120 minutes, which gives 3 minutes per move
>(on average, and ignoring Fischer increment -- if any).
>
>Seems likely that they could have easily finished the pv move at 18 ply, if the
>branching factor was 4.
>
>Don't tell me -- my 8th grade math level is getting in the way again.
>;-)

Do you really believe they searched 4 nodes *only* at first ply?

18 ply with bf of 4 is x*4^17, where x is somewhere from 40 to 1000 depending on
how many nodes qsearch needs.

for 32 nodes ridiculous minimum (say - no qsearch) it will be:
32x4^17/200M = 46 minutes to complete 18 ply.

-Andrew-



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