ECF grades compared with FIDE ratings

General discussions about grading.
Brian Towers
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Re: ECF grades compared with FIDE ratings

Post by Brian Towers » Tue Feb 07, 2017 7:08 pm

Ian Thompson wrote:
Adam Raoof wrote:The problem with fide ratings is that they don't capture 100 percent of the games played, whereas Ecf grading does.
Really? If you look at my ECF, FIDE and USCF records you'll find I played 60 standard play games in total between 1 July 2015 and 30 June 2016, of which 35 were ECF graded, 30 were FIDE rated, 16 were both ECF graded and FIDE rated and 9 were USCF rated only.
I was stunned last year to discover that the ICF had automagically picked up my FIDE rated games in England and incorporated them into my rating. Once they get properly to grips with modern computer technology no doubt the ECF will follow suit, but in the meantime I think you can have them incorporate your non English FIDE rated games if you tell them. Quite possibly they will also be able to incorporate USCF ones as well (as long as they have a conversion factor) if you pass on the details.
Ah, but I was so much older then. I'm younger than that now.

Roger de Coverly
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Re: ECF grades compared with FIDE ratings

Post by Roger de Coverly » Tue Feb 07, 2017 7:14 pm

Brian Towers wrote: but in the meantime I think you can have them incorporate your non English FIDE rated games if you tell them. Quite possibly they will also be able to incorporate USCF ones as well (as long as they have a conversion factor) if you pass on the details.
ECF members can have any non-English results (not just FIDE rated ones) incorporated in their ECF grade, subject to giving advance notice of the intention to play. That also applies to playing non-ECF events in Wales, Scotland and Ireland.

The method of notification hasn't changed in over twenty years, apart from moving to email.

Ian Thompson
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Re: ECF grades compared with FIDE ratings

Post by Ian Thompson » Tue Feb 07, 2017 7:48 pm

Brian Towers wrote:I think you can have them incorporate your non English FIDE rated games if you tell them. Quite possibly they will also be able to incorporate USCF ones as well (as long as they have a conversion factor) if you pass on the details.
You can, and I used to do that, for both foreign FIDE rated games and USCF rated games. I stopped doing so some years ago when the ECF changed the conversion formula from FIDE to ECF to one that was obviously statistically unsound and underestimated a foreign player's ECF grade.

Roger de Coverly
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Re: ECF grades compared with FIDE ratings

Post by Roger de Coverly » Tue Feb 07, 2017 7:58 pm

Ian Thompson wrote:I stopped doing so some years ago when the ECF changed the conversion formula from FIDE to ECF to one that was obviously statistically unsound and underestimated a foreign player's ECF grade.
That would be the one where they used a formula of (FIDE-1250)/5 = ECF/BCF.

That would convert 2200 to 190, 2000 to 150 and 1800 to 110 and a case of blind stupidity in interpretation when running a least squares test. In partial fairness it was at a time when the minimum FIDE rating had been 2000/ 1800 for some years and a number of 150 players in the 4NCL had 2000 FIDE by virtue of the FIDE system only counting the top half of their performances.

LawrenceCooper
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Re: ECF grades compared with FIDE ratings

Post by LawrenceCooper » Tue Feb 07, 2017 8:03 pm

Roger de Coverly wrote:
Ian Thompson wrote:I stopped doing so some years ago when the ECF changed the conversion formula from FIDE to ECF to one that was obviously statistically unsound and underestimated a foreign player's ECF grade.
That would be the one where they used a formula of (FIDE-1250)/5 = ECF/BCF.

That would convert 2200 to 190, 2000 to 150 and 1800 to 110 and a case of blind stupidity in interpretation when running a least squares test. In partial fairness it was at a time when the minimum FIDE rating had been 2000/ 1800 for some years and a number of 150 players in the 4NCL had 2000 FIDE by virtue of the FIDE system only counting the top half of their performances.
I also remember x8 + 600 but no idea how long ago that was now.

Brian Towers
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Re: ECF grades compared with FIDE ratings

Post by Brian Towers » Tue Feb 07, 2017 8:27 pm

Roger de Coverly wrote:
Ian Thompson wrote:I stopped doing so some years ago when the ECF changed the conversion formula from FIDE to ECF to one that was obviously statistically unsound and underestimated a foreign player's ECF grade.
That would be the one where they used a formula of (FIDE-1250)/5 = ECF/BCF.
Is that still the case? Sounds like a sandbagger's dream!
Ah, but I was so much older then. I'm younger than that now.

Ian Thompson
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Re: ECF grades compared with FIDE ratings

Post by Ian Thompson » Tue Feb 07, 2017 8:30 pm

Roger de Coverly wrote:That would be the one where they used a formula of (FIDE-1250)/5 = ECF/BCF.
I can't remember for sure, but suspect it wasn't that formula. It was definitely whilst the lower limit for FIDE ratings was 2000. The previously used formula was definitely ECF = (FIDE - 600)/8.

What they did was to calculate a conversion formula by comparing the ECF grades and FIDE ratings of everyone who had both. That doesn't work at the bottom end of FIDE ratings. It will obviously underestimate the ECF grade of someone with a low FIDE rating.

Why is it wrong? Suppose the correct (but unknown) conversion is ECF = (FIDE - 600)/8. Someone with an ECF grade of 160 has a good tournament, puts in a grading performance of 180 and gets a FIDE rating of 2040. Someone with an ECF grade of 190 has a bad tournament, puts in a grading performance of 170 and has a FIDE rating performance of 1960, but it's not published because it's below 2000. The ECF would then say the correct conversion is ECF 160 = FIDE 2040.

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Adam Raoof
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Re: ECF grades compared with FIDE ratings

Post by Adam Raoof » Tue Feb 07, 2017 8:33 pm

Ian Thompson wrote:
Adam Raoof wrote:The problem with fide ratings is that they don't capture 100 percent of the games played, whereas Ecf grading does.
Really? If you look at my ECF, FIDE and USCF records you'll find I played 60 standard play games in total between 1 July 2015 and 30 June 2016, of which 35 were ECF graded, 30 were FIDE rated, 16 were both ECF graded and FIDE rated and 9 were USCF rated only.

So far this season, from 1 July 2016, the numbers are 13 games played, 9 ECF graded, 8 FIDE rated and 4 both ECF graded and FIDE rated (and it would have been 18 played, 9 ECF, 13 FIDE, 4 both if I hadn't had to withdraw from a tournament after 4 rounds due to illness).
However the lower your grade the more likely it will be that in a FIDE rated event you will play a number of players without a rating. Those games will not even be recorded on the ratings.fide.com server, let alone affect your rating. The opposite is the case with ECF grading - all games played in a graded event count. At some point that will hopefully change.

Paul Cooksey
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Re: ECF grades compared with FIDE ratings

Post by Paul Cooksey » Tue Feb 07, 2017 8:42 pm

I think the point about playing strength is indeed relevant, over 200 ecf I think most people consider their fide rating more important

Roger de Coverly
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Re: ECF grades compared with FIDE ratings

Post by Roger de Coverly » Tue Feb 07, 2017 10:07 pm

Ian Thompson wrote: I can't remember for sure, but suspect it wasn't that formula. It was definitely whilst the lower limit for FIDE ratings was 2000. The previously used formula was definitely ECF = (FIDE - 600)/8.
Discussions on the SCCU site put the change to the formula with a 5 at October 2002. At about the same time, FIDE lowered their minimum rating to 1800.
http://www.sccu.ndo.co.uk/0203/let.htm

The erroneous formula carried on for several years. It's still in the 2008 Diary for example.

By 2010, the *8 multiplier had been restored
http://www.ecforum.org.uk/viewtopic.php?p=32051#p32051

Nick Grey
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Re: ECF grades compared with FIDE ratings

Post by Nick Grey » Sat Feb 11, 2017 12:23 am

This formula has always been correct. The formula for those with BCF>216 was the one with the minus 1250 & 5.

Far more interesting snippets in the rjh open forum on having for example lower graded players in a team to allow more higher graded players in a team with competitions based on average grading. And a reminder of negative grades!

 

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