40 point rule

General discussions about ratings.
Roger de Coverly
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Re: 40 point rule

Post by Roger de Coverly » Thu Nov 28, 2013 9:33 am

Greg Breed wrote:The 40 point rule is not applicable to new players whether junior or not.
You miss the point of my comment. A new player even if eventually able to achieve "average" status now circa 140, may not attain this standard of play in their first grading period. So let's assume they get playing results of 100. In their second grading period, assume they are now playing to 140 standard. So when they play and beat a player with a grade of 80, they score 130 for the game, whereas their counterpart with a 140 grade scores 150. It can take a grading period or two for this effect to wear off. Other than with Juniors, the system has no official method of disregarding a published grade, even if it's an E grade on 9 games only.

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Greg Breed
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Re: 40 point rule

Post by Greg Breed » Thu Nov 28, 2013 11:24 am

Roger if they played at 100 in year 1 it is a little bit unlikely that they will suddenly jump to 140 in year 2. If they were a 140 to begin with or even just rusty, then a couple of new grades later it will sort itself out as you say. In fact if they manage to get 30 or more games in they will likely have a very accurate grade after. I don't see a problem.
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Roger de Coverly
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Re: 40 point rule

Post by Roger de Coverly » Thu Nov 28, 2013 11:37 am

Greg Breed wrote:Roger if they played at 100 in year 1 it is a little bit unlikely that they will suddenly jump to 140 in year 2. If they were a 140 to begin with or even just rusty, then a couple of new grades later it will sort itself out as you say.
Remember that a couple of new grades is a period of at least a year and in the past, at least two years. But it's definitely the 40 point rule that deflates their grade. If a totally new player scores exactly the same against equivalent opposition as a player with a now obsolete grade, the ungraded player ends up with a supposedly higher ranking.

It's not really much of a problem any more because Juniors are treated as new players and new adult players are so few in number.

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Greg Breed
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Re: 40 point rule

Post by Greg Breed » Thu Nov 28, 2013 12:24 pm

Roger de Coverly wrote:If a totally new player scores exactly the same against equivalent opposition as a player with a now obsolete grade, the ungraded player ends up with a supposedly higher ranking.
I see your point, but it would all work out in the end i'm sure.
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Mike Gunn
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Re: 40 point rule

Post by Mike Gunn » Sat Nov 30, 2013 11:18 am

There is a (grading theory) reason why you apply the 10 point rule at both ends, to do with how both the ECF and ELO system are both modelling the probabilities of winning of losing. Although you could modify this assumption non-symmetrically (and I seem to have experienced more -90s than +90s) it would change the theory to something rather more complicated (the probability interpretation of the grading process would no longer hold).

Jeff Clare
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Re: 40 point rule

Post by Jeff Clare » Fri Jan 29, 2016 10:15 pm

I have played 1 graded game against a player with a grade of 154 which I lost. I have an estimated grade of 75 so if I understand things correctly my opponent will score 164?

My next game is against an ungraded player. Will these games count toward my grading or not and. If they do count, how will I score them?

Over the next few weeks I intend to play a number of games against players who have grades ranging from 85 to 220.

Roger de Coverly
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Re: 40 point rule

Post by Roger de Coverly » Fri Jan 29, 2016 11:30 pm

Jeff Clare wrote: My next game is against an ungraded player. Will these games count toward my grading or not and. If they do count, how will I score them?
All games count, but you won't be able to work out your performance until the ECF's computers have cogitated and reworked all the estimates. The next run of this is as at the end of July.

Nick Grey
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Re: 40 point rule

Post by Nick Grey » Sat Jan 30, 2016 12:14 am

I agree with Mike Gunn on this. Could not work out why my Jan went down rather than up. Almost certainly due to more minus 90s in the past. Ever.
I'm also assuming the 40 point rules in Jan-Jun is against the Jan 16 grades & not July 15.

I try not to worry about it my play is far more volatile than it ever used to be.

Paul Dargan
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Re: 40 point rule

Post by Paul Dargan » Sun Jan 31, 2016 5:58 am

@ Nick Grey

I believe that the 40 point rule for previous periods is fixed ... so just because you grade has gone up - those old games you played effectively have the grading points you earned in each game frozen (in the same way that your opponents' grades are not updated).

It's annoying if you're improving fast or a new joiner/returner - you just need to play more games to overcome the 'drag' factor.

Paul

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