Rating/grading bounds correlations
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Rating/grading bounds correlations
What are people's view of the best correlations between bounds for tournament sections and/or grading prizes, please?
One could use the formula of FIDE = 7.5 * ECF + 700.
However, that seems to put most ECF grades - to my eye anyway - at too high a FIDE level.
What do others suggest?
One could use the formula of FIDE = 7.5 * ECF + 700.
However, that seems to put most ECF grades - to my eye anyway - at too high a FIDE level.
What do others suggest?
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Re: Rating/grading bounds correlations
The 4NCL seem to agree with you by imposing an additional conditions on eligibility for their under 2000 tournaments, that players have to be under 175 as well.Paul McKeown wrote: ↑Sun Sep 01, 2019 6:55 pmHowever, that seems to put most ECF grades - to my eye anyway - at too high a FIDE level.
What do others suggest?
The rankings implied by the ECF grades are likely to be more reliable than those implied by FIDE ratings, particularly for improving but less active juniors and those who play them.
Re: Rating/grading bounds correlations
"One could use the formula of FIDE = 7.5 * ECF + 700"
Alternatively -
FIDE = (7.5 * ECF) + 600
works much better for me.
I'm not a good yardstick, though.
Alternatively -
FIDE = (7.5 * ECF) + 600
works much better for me.
I'm not a good yardstick, though.
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Re: Rating/grading bounds correlations
An empirical survey could be done, comparing current players with both a FIDE rating and an ECF grading.
JP Wilkinson carried out such a survey, but it was a very long time ago, last century, in one of the British chess magazines. I no longer have the details except for his formula itself: (ECF * 5.701) + 1136 = Elo rating.
JP Wilkinson carried out such a survey, but it was a very long time ago, last century, in one of the British chess magazines. I no longer have the details except for his formula itself: (ECF * 5.701) + 1136 = Elo rating.
Re: Rating/grading bounds correlations
That's food for thought...
Though I have my doubts whether any ECF 'statto' would even bother to repeat the experiment at present...
JP Wilkinson's formula, above, shows its age when the results are churned out...
21st century developments have overtaken it and a race to the biggger bottoms of the grading & rating scales/lists have left it hanging in the upper air...
Though I have my doubts whether any ECF 'statto' would even bother to repeat the experiment at present...
JP Wilkinson's formula, above, shows its age when the results are churned out...
21st century developments have overtaken it and a race to the biggger bottoms of the grading & rating scales/lists have left it hanging in the upper air...
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Re: Rating/grading bounds correlations
We are in danger of going over old ground. We've certainly chronicled the work done in this thread:
viewtopic.php?f=4&t=3994
Basically I started the discussion in 2012 as an interested observer then when I "volunteered" as grading manager, instituted a change after listening to forumites. The formula was reviewed in 2017.
When determining sections I know organisers aren't that happy with it, as basically the "averaging" means 50% of players are overgraded in one list. However some organisers need to convert the other way round. Moving to a four digit grade will simplify the situation (I hope).
Brian Valentine
Manager of ECF Grading
viewtopic.php?f=4&t=3994
Basically I started the discussion in 2012 as an interested observer then when I "volunteered" as grading manager, instituted a change after listening to forumites. The formula was reviewed in 2017.
When determining sections I know organisers aren't that happy with it, as basically the "averaging" means 50% of players are overgraded in one list. However some organisers need to convert the other way round. Moving to a four digit grade will simplify the situation (I hope).
Brian Valentine
Manager of ECF Grading
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Re: Rating/grading bounds correlations
Brian, thank you for all the work that you have put into improving the grading system over many years, now, and good luck with the conversion to four digits (hugely overdue*) and monthly updates (one hopes this one is not a "Bridge too Far").
What would you suggest are suitable corresponding ECF boundaries mapping to the following FIDE ratings:
* ironically drawing us into Caissic alignment with our neighbours, as a chaotic and inchoate narrow political faction struggles insanely, spittle-flecked, to sunder the country's political and economic alignment with those selfsame neighbours
What would you suggest are suitable corresponding ECF boundaries mapping to the following FIDE ratings:
- 2200
- 2000
- 1800
- 1600
- 1400
* ironically drawing us into Caissic alignment with our neighbours, as a chaotic and inchoate narrow political faction struggles insanely, spittle-flecked, to sunder the country's political and economic alignment with those selfsame neighbours
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Re: Rating/grading bounds correlations
Ok, I'm going to make a proposal:
Am I off-beam?
Or am I just attempting the impossible, riding two horses, the stably rated adult population and the under-rated junior population?
I suspect the 2200 equivalent is probably more like 205, but prejudiced in favour of straight lines!
- 2200 approx 210 (official formula gives 200)
- 2000 approx 185 (173)
- 1800 approx 160 (147)
- 1600 approx 135 (120)
- 1400 approx 110 (93)
Am I off-beam?
Or am I just attempting the impossible, riding two horses, the stably rated adult population and the under-rated junior population?
I suspect the 2200 equivalent is probably more like 205, but prejudiced in favour of straight lines!
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Re: Rating/grading bounds correlations
If you use the FIDE ratings as a cut off, you need to be pragmatic. Check how many sharks with lower ECF grades you might attract and whether you want them.Paul McKeown wrote: ↑Tue Sep 03, 2019 12:16 am
Or am I just attempting the impossible, riding two horses, the stably rated adult population and the under-rated junior population?
I suspect the 2200 equivalent is probably more like 205, but prejudiced in favour of straight lines!
as a general premise, if you wanted to rank English players and players active in England by relative strength, the ECF grades are a more reliable guide.
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Re: Rating/grading bounds correlations
Roger, rather a gnomic utterance. Pinning you down on a number is the devil's own job. Would you care to make an actual suggestion? (I'm trying to set fair cut-offs for grading prizes and section entries, not some abstruse "ranking" exercise.)
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Re: Rating/grading bounds correlations
You could fall in line with the 4NCL Congresses or alternatively diverge from them.Paul McKeown wrote: ↑Tue Sep 03, 2019 1:12 amWould you care to make an actual suggestion? (I'm trying to set fair cut-offs for grading prizes and section entries, not some abstruse "ranking" exercise.)
4NCL Congresses wrote: FIDE Rated U2000: Open to (1) FIDE rated players rated below 2000 FIDE; (2) players without a FIDE rating graded below 175 ECF *
FIDE rating graded below 175 ECF *
* If FIDE rated players also have an ECF grade, their ECF grade must be below 175.
Re: Rating/grading bounds correlations
Reminds me of -Paul McKeown wrote: ↑Tue Sep 03, 2019 12:16 amOk, I'm going to make a proposal:
Does this reflect reality?
- 2200 approx 210 (official formula gives 200)
- 2000 approx 185 (173)
- 1800 approx 160 (147)
- 1600 approx 135 (120)
- 1400 approx 110 (93)
Am I off-beam?
Or am I just attempting the impossible, riding two horses, the stably rated adult population and the under-rated junior population?
I suspect the 2200 equivalent is probably more like 205, but prejudiced in favour of straight lines!
(The Brothers Karamazov)Even if parallel lines do meet and I see it myself, I shall see it and say that they’ve met, but still I won’t accept it.
Last edited by John McKenna on Tue Sep 03, 2019 2:11 am, edited 1 time in total.
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Re: Rating/grading bounds correlations
Thanks, Roger, but isn't that just per the current formula (FIDE = 7.5 * ECF + 700), rounded to the nearest nice number?
(It's also agrees exactly with the old formula, FIDE = 8 * ECF + 600, which held from the 1970s will into the 2000s...)
Do you think 175 and 2000 are equivalent? (My impression is that 2000 FIDE is a generally a little bit - not hugely - better than 175; lower down, though, the divergences can be much greater, particularly with kids.)
(It's also agrees exactly with the old formula, FIDE = 8 * ECF + 600, which held from the 1970s will into the 2000s...)
Do you think 175 and 2000 are equivalent? (My impression is that 2000 FIDE is a generally a little bit - not hugely - better than 175; lower down, though, the divergences can be much greater, particularly with kids.)
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Re: Rating/grading bounds correlations
I am of the view that it is up to the organiser and what they are trying to achieve. As I obliquely stated above it depends on whether the primacy is FIDE or ECF. The 4NCL approach given above is tried and tested. With a modest bit of mathematics a more complicated approach can be derived. If a player has only a FIDE or ECF number then use that. If they have both use the average of FIDE and converted ECF.Paul McKeown wrote: ↑Mon Sep 02, 2019 7:59 pmBrian, thank you for all the work that you have put into improving the grading system over many years, now, and good luck with the conversion to four digits (hugely overdue*) and monthly updates (one hopes this one is not a "Bridge too Far").
What would you suggest are suitable corresponding ECF boundaries mapping to the following FIDE ratings:Any tips from your expertise in this would be hugely appreciated...
- 2200
- 2000
- 1800
- 1600
- 1400
* ironically drawing us into Caissic alignment with our neighbours, as a chaotic and inchoate narrow political faction struggles insanely, spittle-flecked, to sunder the country's political and economic alignment with those selfsame neighbours
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Re: Rating/grading bounds correlations
Perhaps that could be followed through into the number used for pairings. It would avoid the apparent randomisation when the top half by FIDE rating meets the bottom half in the first round, but you get a game between players with identical ECF grades.Brian Valentine wrote: ↑Tue Sep 03, 2019 7:39 amIf a player has only a FIDE or ECF number then use that. If they have both use the average of FIDE and converted ECF.
Extremities of where players are out of line between their FIDE ratings and ECF grades are improved juniors who haven't played much FIDE rated chess. These would have ECF grades much higher than their FIDE ratings. Organisers need to decide whether they are happy with 180+ players in a tournament perhaps intended for under 150s. The other extremity is older players returning to FIDE rated chess and reactivating a higher rating from years or decades earlier. Does the organiser insist they play in a higher section than implied by their ECF grade?