Elo or Clarke national grading list?

General discussions about ratings.

What is your preferred calculation system for England's national grading list?

Clarke (current ECF system)
14
33%
Elo (current FIDE system)
27
64%
None of the Above
1
2%
 
Total votes: 42

Roger de Coverly
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Re: Elo or Clarke national grading list?

Post by Roger de Coverly » Fri Sep 30, 2011 5:17 pm

E Michael White wrote:It is sometimes suggested that switching to an Elo basis and increasing junior k-factors would solve the problems, as used by other chess federations. .
The Scots, who retain a base list which only changes annually, have rules which can cause a previous rating to be dumped and the player treated again as a new player. At least, that's what I think they say. So if the performance rating is 200 points (equiv 25 ECF) above the published rating (and a junior?) the old rating is discarded. If they adopted more frequent updates, this might reduce the problem. Almost any rating system will struggle with players who are annoyingly inconsistent.

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John Upham
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Re: Elo or Clarke national grading list?

Post by John Upham » Fri Sep 30, 2011 5:36 pm

Roger de Coverly wrote: Pretty essential on something that everyone has an opinion on, like grading.
It has now become clear. Roger is aware of issues that everyone (and surely that must mean everyone in the whole wide world and possibly beyond) has an opinion on.

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Roger de Coverly
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Re: Elo or Clarke national grading list?

Post by Roger de Coverly » Fri Sep 30, 2011 5:45 pm

John Upham wrote:
It has now become clear. Roger is aware of issues that everyone (and surely that must mean everyone in the whole wide world and possibly beyond) has an opinion on.
.
I really don't know what you are rabbiting on about. It's obviously surely that a change in the grading system to one using an Elo methodology has to have widespread support. There are a handful of critics who dislike the idea of half yearly publication of grades. The very large majority in Council in favour means their voices, on this issue, can be disregarded. So half yearly publication of grades has wide support, even though we don't really know, for sure, the precise mechanics.

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John Upham
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Re: Elo or Clarke national grading list?

Post by John Upham » Fri Sep 30, 2011 5:55 pm

Roger de Coverly wrote: I really don't know what you are rabbiting on about.
I am relieved: I thought you were aware of all of the issues that everyone has an opinion on and post on their behalf?
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Mike Gunn
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Re: Elo or Clarke national grading list?

Post by Mike Gunn » Fri Sep 30, 2011 7:32 pm

Arguably the Clarke system is better for rapidly improving juniors (because it discards earlier results quicker if the junior is playing a reasonable number of games per year). There was a post on this from the father of a rapidly improving junior recently ...

Paul Cooksey

Re: Elo or Clarke national grading list?

Post by Paul Cooksey » Fri Sep 30, 2011 7:37 pm

Mike Gunn wrote:Arguably the Clarke system is better for rapidly improving juniors (because it discards earlier results quicker if the junior is playing a reasonable number of games per year). There was a post on this from the father of a rapidly improving junior recently ...
Compared to Elo as used by FIDE, certainly. Although arguably to the detriment of the established players they are playing. We have discussed seperately increasing k to mitigate the issue with Elo moving too slowly for juniors. I support that idea.

Alex Holowczak
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Re: Elo or Clarke national grading list?

Post by Alex Holowczak » Fri Sep 30, 2011 7:41 pm

Having k means that you can make all sorts of changes to get around this sort of problem. As Paul states, you can have a special k (other cornflake manufacturers are available) for users. To deal with overshooting, you can have k as a function of the number of games a player plays in a rating period.

Kevin Thurlow
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Re: Elo or Clarke national grading list?

Post by Kevin Thurlow » Mon Oct 03, 2011 12:13 pm

If you adjust "K" you can fiddle the ratings. So if two players with identical ratings get identical results, and you give one a K of 100 and the other a K of 10, they will have different ratings. So any such system must be seen to be fair.
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