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Subject: Re: Green List formula

Author: Dave Gomboc

Date: 08:51:52 01/18/00

Go up one level in this thread


On January 18, 2000 at 11:45:37, Will Singleton wrote:

>On January 18, 2000 at 08:49:48, Vincent Diepeveen wrote:
>
>>"R(mhz)    rating/log(mhz)/100.  Shows the performance of an account,
>>          taking into consideration the cpu speed."
>>
>>First of all Will is taking into account for his formula a logaritme,
>>combines that with rating and computer Mhz.
>>
>>This assumes a logarithmic connection between Mhz of a machine and its
>>rating.
>>
>>Obviously this is wrong.
>>
>>Let's take crafty:
>>
>>Wild        2148  [6]   195    50     8   253   2148 (06-Aug-1999)
>>Bullet      3033       6241  1412  1018  8671   3191 (27-Oct-1999)
>>Blitz       2858      48312 12919  8716 69947   3268 (27-Oct-1999)
>>Standard    2550       3761  1496  1117  6374   2785 (08-Aug-1999)
>>
>>Machine = 4x400 = 1600Mhz
>>rating  = 2550
>>
>>So this would make
>>   R(mhz) = 25.50 / log(1600) = 7.95
>>
>>Now that sounds a bit low to me personal already.
>>
>>Let's now assume that Bob wants to top the green list:
>>
>>  He needs 11.0 then as R(Mhz) to top it more or less.
>>
>>So 11.0 = rating / 100*log(1600)
>>   rating = 11 * 100 * log(1600) = 3525
>>
>>So crafty needs an incredible rating of 3525 to top the greenlist.
>>Good luck Bob!
>>
>>Why invent a formula if it's in advance already dead wrong?
>>
>>Rating is not based upon the 10th log of something.
>>It SURE does not represent performance taking into account
>>the machine speed.
>>
>>
>>Vincent
>
>
>Couple things.  First, crafty's efficiency isn't 100%, I don't believe.  I use a
>figure like 75-80% when calculating the effect of multiple cpus, which is just
>an approximation.  But you're right, the formula seems to work better in a
>narrow range.  Have a better formula for me?
>
>But come on, Vincent, the whole list is just an approximation.  Many folks feel
>that ICC ratings have little real-world significance, due to the factors present
>in server play.  Again, the list is just for entertainment purposes, it doesn't
>purport to be anything official.
>
>Having said that, on ICC one does see a general correlation between ratings and
>perceived strength.
>
>Will

Amusingly enough, one of the points considered in "The Rating of Chessplayers,
Past and Present" by Elo is using a distribution based on log10 instead of the
normal distribution, because the tails of the normal distribution are too low to
match reality.

Dave




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