Irish Chess Union Rating Conversion?

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Steve Lovell
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Irish Chess Union Rating Conversion?

Post by Steve Lovell » Sun Oct 13, 2019 2:38 pm

Hi there,

I've had an Irish family trio enter my tournament. Two of the three have FIDE ratings in addition to their Irish Chess Union rating, but nothing for the third player (who in ICU rating terms is the middle of the three). Has anyone much experience with the ICU ratings and how they should be handled for calculating an ECF equivalent?

Using the FIDE -> ECF formula but starting from an ICU rating instead seems wrong as while the ICU rating is elo style, that doesn't guarantee equivalence (compare USCF).

Are there any reasonably trustworthy conversions available?

Cheers,

Steve
Steve Lovell
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IM Jack Rudd
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Re: Irish Chess Union Rating Conversion?

Post by IM Jack Rudd » Sun Oct 13, 2019 2:47 pm

I suggest you do a linear interpolation from the FIDE and ICU ratings you have to work out what FIDE rating that player would probably have if they had one, and then convert from that.

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Steve Lovell
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Re: Irish Chess Union Rating Conversion?

Post by Steve Lovell » Mon Oct 14, 2019 9:22 am

Cheers Jack. That's exactly what I've done. The resulting formula was (approximately) ECF = (ICU/10) -18.

I'd have done this with a bit more confidence except that the result is quite near a section grade boundary (just below).

If I get some time after our event, I may make an informal study of the subject to aid anyone else who may find themselves in the same situation.
Steve Lovell
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Bury St Edmunds - Chess Club Secretary and Congress Organiser
Bury Area Chess League - Webmaster

Ian Jamieson
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Re: Irish Chess Union Rating Conversion?

Post by Ian Jamieson » Tue Oct 15, 2019 3:34 pm

By coincidence this formula (or the equivalent ICU=ECF*10+180) is the same formula Chess Scotland use for converting ECF grades.

Roger de Coverly
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Re: Irish Chess Union Rating Conversion?

Post by Roger de Coverly » Tue Oct 15, 2019 5:18 pm

Ian Jamieson wrote:
Tue Oct 15, 2019 3:34 pm
By coincidence this formula (or the equivalent ICU=ECF*10+180) is the same formula Chess Scotland use for converting ECF grades.
It's probably not a coincidence as a few years ago, the ECF moved the centre of its grading list from around the 115-120 level to around the 140 level. So modestly graded Irish or Scottish players taking part in English events found themselves 20 to 25 ECF points higher.

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