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PostPosted: Sun Jan 15, 2012 2:37 pm 
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... my rating performance for 4 out of 6 was 194 according to the table sent to ECF. I play one more game and win to get to 5 out of 7 and my rating perfomance drops to 193.

Mr Grading Officer , is this why the ECF rating system is not popular with some?

Paul

PS Just in case ... I am not that bothered but wondered why these things happen from a mathematical point of view!


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PostPosted: Sun Jan 15, 2012 6:06 pm 
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In the ECF system you gain:
opponents grade + 50 for a win
oppenents grade for a draw
opponents grade - 50 for a loss. There are exceptions to this if the difference between your grade and your opponents grade is larger than 40 points, but for the sake of simplicity I will ignore these.

Consider the case when you play 6 games for a performance of 194, and then in your next game you face a 135 player. The maximum number of points you are going to be able to gain from this game is 185, assuming you win. This is lower than your previous average performance, and thus it will drop your average performance.


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PostPosted: Sun Jan 15, 2012 6:12 pm 
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This is (in my opinion) why the elo system used for FIDE and Wales is much better than ECF.

_________________
Tom

The Welsh U16 rapid play Champion (x2) and Welsh U20 Champion
2nd in British U16 Championship
thomas.g.thorpe@googlemail.com


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PostPosted: Sun Jan 15, 2012 6:17 pm 
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Thomas Thorpe wrote:
This is (in my opinion) why the elo system used for FIDE and Wales is much better than ECF.

It's one of the reasons, for sure.


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PostPosted: Sun Jan 15, 2012 6:29 pm 
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Thank you Rob

Of course it does not explain in this case as my opponent was 167


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PostPosted: Sun Jan 15, 2012 8:09 pm 
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The only other thing I can think of is that you may have played an ungraded player (or more than one) who now have a lower estimate than they used to.


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PostPosted: Sun Jan 15, 2012 9:57 pm 
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PaulHatchett wrote:
... my rating performance for 4 out of 6 was 194 according to the table sent to ECF. I play one more game and win to get to 5 out of 7 and my rating perfomance drops to 193.

Mr Grading Officer , is this why the ECF rating system is not popular with some?

Paul

PS Just in case ... I am not that bothered but wondered why these things happen from a mathematical point of view!


Hi Paul

here is the explanation for it - Humphrey Andolo is Ungraded - http://www.ecfgrading.org.uk/?ref=233310H - shows up as having previous grades around the 170+ mark but is averaging 189 this season.

Here is a breakdown of your results so far this season - first table is the 6 games sent for half year grades - then I've added a table which includes the win against Geoff Taylor recently based 7 games. - You've moved up from 193 - to 196 not down which should please you :)

see following link - http://www.chessit.co.uk/Grading/Grading%20Queries.htm

If you like I can change the estimate of H Andolo's grade for calculation purposes on the spreadsheet I'm running to reflect this ( maybe estimate him at 180 ) or if I give him no grade your result against him will change as his grade changes in line with the ECF.

This is why you shouldn't take it for granted that the league spreadsheet will calculate the results correctly when it comes to ungraded players.


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PostPosted: Sun Jan 15, 2012 11:46 pm 
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Thank you Dave. That is why I will never be a grader because these mental gymnastics are a rare gift.

I will leave it in your capable hands but thanks for clearing up this conundrum.

Keep up the good work!

Paul


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PostPosted: Sun Jun 10, 2012 10:13 am 
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You still have to play 30 games to recieve your published grade for the next season, i.e. if 6 games are played only then your grading performance to date still has to be added to the previous 24 games played. So if your published grade at the start of the season was 180, simply take 180 x 24 and add that total to the grading performance to date. This then will give your average grade for the season. Why is the Welsh Grade better? This system works fine.


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