| Angelo De Pa1ma 2005-04-11, 5:59 pm |
| Thanks again. Not only do I now get it, I also realize it would be stupid to
average and use performance ratings.
I remember way back when seeing a summation sign in there, but it wasn't to
add opps' ratings it was to add up the expectations from each game.
"George John" <george@neosoft.com> wrote in message
news:1112646519.905420.13470@z14g2000cwz.googlegroups.com...
quote:
> Angelo De Pa1ma wrote:
>
> Angelo,
>
> manner, or
>
> Bingo! Correct!
>
> expectation
> expectation for
> individually.
>
> Correct!
>
> [SNIP]
> *not*
> fantasy
>
> Looking at it from the POV of what impact each rating point difference
> has, I think the idea behind this is the results of games become
> increasingly less significant, proportionately speaking, as the rating
> differences grow greater. IOW, as rating differences change it becomes
> more uncertain what the result of that game means relative to 'true'
> rating strength. If a player starts losing a lot to players rated
> exactly the same, that means quite a bit more than if they lose to
> players rated 400 points higher, and a whole lot more than if they are
> losing to players rated 800 points higher (as examples).
>
> And, while it is true a player does lose more points as they lose to
> players with increasingly lower ratings, the incremental impact
> decreases for each additional increase in rating differences. For
> example, the number of points lost to losing to a player rated 800
> points less is not much more than against one rated 400 points less.
> The largest incremental difference in rating change is between someone
> your own rating and one rated one point less.
>
> You provided a good example when you said that scoring 4.5 against your
> opponents was much easier than scoring 2.5 against 5, 2300 rated
> opponents. Five games played by only 2300 rated players have more
> significance (rating-wise) than games played with significant rating
> differences like the ones you played. So, your 2300 result has
> correspondingly less 'meaning' WRT to adjusting your rating.
>
> I hope this helps more than hurts your understand. ;-) I'm not a
> statistician, so please consider this a layman's perspective.
>
> BTW, another quick tip on the rating system which you may or may not
> already know, the expected score formula is calibrated on differences
> of 400. For example:
>
> Rating Difference, Expected Score
> -1200, 1.0 out of 1001 games
> -800, 1.0 out of 101 games
> -400, 1.0 out of 11 games
> 0, 1.0 out of 2 games
> 400, 10.0 out of 11 games
> 800, 100.0 out of 101 games
> 1200, 1000.0 out of 1001 games
>
> Best regards,
>
> [SNIP]
>
|