Author: Vincent Diepeveen
Date: 19:06:58 06/02/02
Go up one level in this thread
On June 01, 2002 at 13:14:58, Andrew Dados wrote: Hello, of course there are problems with the rating truths. For example here it says someone 1000 points lower rated has 0.003 chance against me. Or 3 out of 1000 games. However OTB, it is not 3 out of 1000 games. Not even 1 out of 1000. It is 0 out of 1000 and nothing else. Idem for up to 600 points. The rating idea doesn't work when a player who is titled plays a < 1700 player simply. >>>>Here is a little table: >>>> >>>>Win expectency for a difference of 0 points is 0.5 >>>>Win expectency for a difference of 100 points is 0.359935 >>>>Win expectency for a difference of 200 points is 0.240253 >>>>Win expectency for a difference of 300 points is 0.15098 >>>>Win expectency for a difference of 400 points is 0.0909091 >>>>Win expectency for a difference of 500 points is 0.0532402 >>>>Win expectency for a difference of 600 points is 0.0306534 >>>>Win expectency for a difference of 700 points is 0.0174721 >>>>Win expectency for a difference of 800 points is 0.00990099 >>>>Win expectency for a difference of 900 points is 0.00559197 >>>>Win expectency for a difference of 1000 points is 0.00315231 >>>> >>>>Notice that for 1000 ELO difference the win expectency is only .3%. >>> >>>I see. So, that is the Elo calculation of Elo for human chess, right? What is >>>giving you the confidence that it works for computers the same way? >> >>What gives you the confidence that it works for humans. >> >>These numbers were not calculated based on statistics of humans games and I >>believe that they are not correct also for humans. >> >>Uri > >Hello Uri. > >I keep noticing there is huge misconception about what ELO numbers are. >So I will try to explain how rating system is defined/build. > >Rating system is based on ONE, single assumption: that distribution of ratings >over big pool of players obeys normal distribution. > >Then we need to build a scale. >That means we need to define '0' point on the scale and also unit of measuring >(what '1 point' means). > >Lets say we define '0' equals 1740 ELO points. Meaning of this number is: >average rating of all players in pool is 1740 in our scale. it is chosen >arbitrarily and can be _any_ number. > >Then we define a unit, say 200 points in such a way, then 200 pts difference >translates to probability of winning equal to 0.75. This is another arbitrary >number, defining our scale. Discussing validity of it is about as sensible as >discussing if 1 meter on earth equals 1 meter on moon. > >So by definition all those numbers from Danns post are valid, that is basis to >calculate players ratings. > >-Andrew-
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.