Author: Dan Homan
Date: 10:12:08 01/18/00
Go up one level in this thread
On January 18, 2000 at 12:56:44, Dan Homan wrote: >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 > >Hi Will, > >Your adjustment does something to correct for the >faster is better rule - and the logrithm accounts for >the fact that faster isn't linearly better, but >Vincent has a point in that (beyond the above considerations) your >adjustment is basically pulled out of thin air. A better >approximation might be to use the general rule that >doubling the speed gives about seventy elo points. >Adjusting for that rule is easy... > >Adjusted Rating = Rating - 70 x log[2](MHz) - 2000 > >(where log[2] is log base 2) It just occurred to me that log[2] doesn't show up on many calculator, so a simple approximation is log[2](x) = 3.322 x log[10](x) (log[10] is just log base 10) So the formula becomes (using log base 10) Adjusted Rating = Rating - 233 x log[10](MHz) - 2000 > >So a 400 MHz machine would have 70 more poinst subtracted >than a 200 MHz machine. The "- 2000" at the end of the formula is >arbitrary and I just put it in so that no one will confuse the adjusted >elo ratings with the FIDE or USCF scale. An added advantage to >this formula is that the end result is still an elo type number, so >win/loss probabilities can be judged in the usual way by comparing >differences between the adjusted ratings. > >One could refine this and adjust for the difference between >G3/G4 and PII/PIII type processors (maybe replacing the MHz >number with a Specint95 for the same machine), but at >this level of approximation I am not sure it is necessary. > > - Dan
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.