Grading timetable (June/July 2013)

General discussions about ratings.
Roger de Coverly
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Re: Grading timetable (June/July 2013)

Post by Roger de Coverly » Sat Jul 27, 2013 1:28 pm

Dewi Jones wrote:I haven't played since 2007 when i Had a 70 grade, I come back, play one season of 25 games, and find i'm a 115
Dewi Jones wrote: but not 45 points worth of more time to think
The ECF did a major reworking of the grading system in 2008. One of the consequences was that the "average" player leapt from around 115 to around 135. For players in the range 50 to 90, the addition could be as much as 50 points.

One of the things you could check is to look back at people you played in 2007 and see if they are still playing and what their grade now is. The ECF grading site has the archive of results from previous seasons, so it knows, even if you have discarded previous scoresheets and results.

You might just have become a better player. It does happen!

MartinCarpenter
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Re: Grading timetable (June/July 2013)

Post by MartinCarpenter » Sat Jul 27, 2013 2:08 pm

There was a very clear way in which people ~200+ might have increased a bit - 200 was about the original fixed point of the revaluation so they didn't gain anything. All the weaker players did of course, some quite a bit. So if they kept beating people lower than them by the same amount they were previously doing you'd expect there to be some increase to work through before things stabilised. Especially if some of them did that much more than others. No idea if its a real effect of course. You'd need to run a lot of numbers to see.

From the several long term ~200 graded York players, only Paul Townsend has crept up into the top 120 and he's definitely playing better than he was a few years back.

The other is that I've certainly got the vague impression that the long term ~170 (old money) or ~180 (new) players have been subject to a little more instability than usual the past year or two. Could be anything of course. Even subjective bias caused by my own grade (and play to be fair ;)) being so random. -22 in half a year is good stuff!

Sean Hewitt
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Re: Grading timetable (June/July 2013)

Post by Sean Hewitt » Sat Jul 27, 2013 3:49 pm

MartinCarpenter wrote:The other is that I've certainly got the vague impression that the long term ~170 (old money) or ~180 (new) players have been subject to a little more instability than usual the past year or two. Could be anything of course. Even subjective bias caused by my own grade (and play to be fair ;)) being so random. -22 in half a year is good stuff!
That, I think, is to do with the change in the calculation method brought in along with 6 month grading lists, confusingly at the same time as the regrading exercise. They now stop counting back when they get to 30 whereas previously they used all of your previous years results, weighted. That introduces volatility. Whether that volatility is a more accurate reflection of current playing strength is a different discussion!

Barry Sandercock
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Re: Grading timetable (June/July 2013)

Post by Barry Sandercock » Sat Jul 27, 2013 4:24 pm

Fide ratings is showing no games for July although e2e4 Sunningdale was 5th-7th July ?

James Coleman
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Re: Grading timetable (June/July 2013)

Post by James Coleman » Sat Jul 27, 2013 4:39 pm

Not too au-fait on the calculation methods so out of interest, what could have caused my grade to go up a few points without playing? Is it the effect of dropping games that are too old to now be included?

LawrenceCooper
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Re: Grading timetable (June/July 2013)

Post by LawrenceCooper » Sat Jul 27, 2013 4:47 pm

Barry Sandercock wrote:Fide ratings is showing no games for July although e2e4 Sunningdale was 5th-7th July ?
It is due to be rated on the August list. That will probably appear on the FIDE site on the 31st July mid afternoon. The rating file was received by FIDE on 7th July: http://ratings.fide.com/tournament_deta ... vent=82271

Barry Sandercock
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Re: Grading timetable (June/July 2013)

Post by Barry Sandercock » Sat Jul 27, 2013 5:41 pm

Thanks for that,Lawrence.

Sean Hewitt
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Re: Grading timetable (June/July 2013)

Post by Sean Hewitt » Sat Jul 27, 2013 5:44 pm

Barry Sandercock wrote:Fide ratings is showing no games for July although e2e4 Sunningdale was 5th-7th July ?
FIDE produces a list once a month, nominally on the 1st of each month and events are rated in the next list after finishing. So an event finishing in July would be rated on 1st August. There is a cut off around 27/28 of the month so events finishing after the cut off have to wait another month before being rated.

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Christopher Kreuzer
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Re: Grading timetable (June/July 2013)

Post by Christopher Kreuzer » Sun Jul 28, 2013 4:53 pm

Good to see the new grades are out (it was that and Adams' game at Dortmund against Caruana that brought me out of summer hibernation!). Interesting to see Jonathan Rogers' thoughts on the top 120 players. I'm in the top 120 players, but by activity rather than ranking... 8)

Not too thrilled about the new format of the database (the old graphs and pie-charts were nice). It is possible to link to individual records, but have not yet found a way to link to dynamic listings. You can link to the top players for example, but twiddle the filter settings and generate a different list and then link to that list, can't seem to do that unless there is a trick to it?

John Hodgson
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Re: Grading timetable (June/July 2013)

Post by John Hodgson » Sun Jul 28, 2013 5:32 pm

Sean Hewitt wrote: That, I think, is to do with the change in the calculation method brought in along with 6 month grading lists, confusingly at the same time as the regrading exercise. They now stop counting back when they get to 30 whereas previously they used all of your previous years results, weighted. That introduces volatility. Whether that volatility is a more accurate reflection of current playing strength is a different discussion!
At a lower level than Jonathan Rogers originally mentioned (say 190-210 grading), I quite often notice established adult players appear with what seem to me 'high' ratings, only to disappear 'where they belong' in the next list (and of course the reverse, though this tends to be masked by the simultaneous introduction of grading inflation).

I gave up statistics when I was at school, but from memory a population size of 30 was supposed to be the minimum to be statistically significant. I don't remember being taught that you had to use 30 if a larger number was available.

It seems to me that the gradings of established adult players who have been playing for years are too volatile. However, if you average out the gradings over two or three lists you get something which better reflects playing strength, which does not change that much.

My subjective feeling is that there is something wrong with the ECF grading methodology. But perhaps a statistician can explain why the ECF system is for the best in all possible worlds.

Andrew Collins
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Re: Grading timetable (June/July 2013)

Post by Andrew Collins » Sun Jul 28, 2013 5:41 pm

John Hodgson wrote:
It seems to me that the gradings of established adult players who have been playing for years are too volatile. However, if you average out the gradings over two or three lists you get something which better reflects playing strength, which does not change that much.
What do you class as too volatile though, +- 10 points or 20 points or more? It seems to me from my looking at the variation in people I have played graded 120-170 approx. that there a significant number of players who have been at +-10 points of their current grade for many years. Which doesn't seem generally that much of a volatile nature

Roger de Coverly
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Re: Grading timetable (June/July 2013)

Post by Roger de Coverly » Sun Jul 28, 2013 6:38 pm

Andrew Collins wrote: It seems to me from my looking at the variation in people I have played graded 120-170 approx. that there a significant number of players who have been at +-10 points of their current grade for many years. Which doesn't seem generally that much of a volatile nature
What's happening now is that if you play enough games to merit an X rating (6 months only), that your grade can jump all over the place if you don't get similar results in the July to December period as distinct from the January to June period. When the lists were annual, these fluctuations would normally average out. With many events taking place once, it's not the same mix from one grading period to the next when six monthly calculations are used.

For top players anyway, if their ECF grade is increasing, is their FIDE rating increasing as well? Bearing in mind that both contain mostly the same games, this may constitute evidence that the wholesale gift of grading points in 2008 to the middle of the distribution is seeping up to the top.

Richard Bates
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Re: Grading timetable (June/July 2013)

Post by Richard Bates » Sun Jul 28, 2013 7:14 pm

Roger de Coverly wrote:
For top players anyway, if their ECF grade is increasing, is their FIDE rating increasing as well? Bearing in mind that both contain mostly the same games, this may constitute evidence that the wholesale gift of grading points in 2008 to the middle of the distribution is seeping up to the top.
Mine's almost certainly rising because my distribution of opponents is heavily skewed to the weaker end by league chess (about 2/3 are weaker). So i've been hoovering up the points (prior to 2009 i had been very consistent at 220 for many lists, which was the breakeven point for the revaluation. My FIDE rating has been and continues to be similary consistent). That and i have some amazing captains for several years who are very good at giving me white ;)

MartinCarpenter
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Re: Grading timetable (June/July 2013)

Post by MartinCarpenter » Sun Jul 28, 2013 7:52 pm

Ideally if someone is playing ~40 games a year then their grade will be +-5 each year with an occassional really bad/good year beyond that. +-20 should be very difficult indeed to achieve, except for juniors.

The limit to the most recent 30 can definitely make things more random - my -22 this time (193 to 171) would I think have been 'merely' ~-15 (190 - 175) on full yearly grades. (Which would be wel deserved as I played pretty awfully last season.).

I guess one interesting thing to test would be if players with >30 games a year (X grades I think?) were getting more volatile results than people playing less than that. If they are then wouldn't that be fairly strong evidence that countback isn't a good idea?

I do also suspect that there's also been a period where the grades for players ~180 (new style) have been settling down. I checked a few of the Yorkshire players around my strength and they're certainly mostly all concentrating around 180 now but several of them have been very up and down on the way. One was down to ~165 at one stage.

Sean Hewitt
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Re: Grading timetable (June/July 2013)

Post by Sean Hewitt » Sun Jul 28, 2013 8:00 pm

I've asked Alex Holowczak, as the Director responsible for grading, if he can get the team to run some simulations. In particular, what effect has the count back to 30 had. I've not seen any evidence that this change was properly tested in advance. They'll also look at whether there is any inflation or stretch in the system.

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