"Jürgen R." wrote in message
...
On Sun, 11 Jul 2004 09:46:55 +0200, "byrne" wrote:

10 , 30 , 50 etc points per 5 or 10 years ?!
GM Korchnoi says 30 points per 10 years
( 2004 - 2600elo= 1994 - 2570elo)

Regards ,
byrne

Anybody who asks this question shows he hasn't understood what a
rating system is.

You can demonstrate easily enough how the average rating has changed
with time; however, you cannot show how the player strength for a
given rating has changed: In order to do this you would need to
measure strength, i.e. you need a rating system...

Rating systems measure *relative* strength, they cannot measure
*absolute* strength.

Jürgen

You could do it (measure the change in player strength for a given rating
over time) with a player of constant strength - say a computer program - and
record it's performance against players of various ratings over time. A
meta-rating system, if you will.

-JEH