Sunday, January 29, 2012

January 2012 ECF Grades

As you are no doubt aware, the preliminary grading list has been published, with the welcome inclusion of the underlying game results data (from 2003 onwards) and a snazzy chart to boot.

In-form David Weston deservedly climbs the Trowbridge table, and he is now the highest graded of our currently active players. Also improving is Dave Marshall, whose grade now more accurately reflects his playing prowess. Louis Burton continues his inexorable climb to the world of 3 digit ratings and Anthony Ransom is also up a couple of points. However everyone else has suffered a set-back. Roy Ludlow in particular appears to have been hard done by. He had below-par results in 2011 and I'm sure he will bounce back in the next grading list.

Indeed it is surprising how easily a handful of results can affect the rating calculations. So that you may judge the accuracy of the ECF's new grading assignments, I have reproduced the January figures below. In the right-most columns I have compared the January 2012 grades with the known performance of each player, using the data available on the Trowbridge website (up to and including the 26th of January).

2011 Standard ECF Performance  Diff
David Weston 149 155 162 -7
Mark Leonard 153 151 154 -3
Derek Rothwell 152 147 144 3
Dave Marshall 141 143 149 -6
Tim Woodward 155 137 143 -6
Gareth Williams 131 129 128 1
Roy Ludlow 131 111 120 -9
Louis Burton 82 91 92 -1
Anthony Ransom 73 75 73 2
Nigel Crucefix 71 67 64 3
Richard White ung 59 56 3

Of the 14 games I've played this season, 11 took place in 2011, but only 6 have been submitted for grading. For some reason the Wiltshire league and the Frome internal club games do not appear in the list of interim results. The grade given to me by the ECF happens to be 3 points less than my actual performance over the last 30 games.

I think the conclusion we should draw is that the ECF grades should be taken with a pinch of salt. They are just numbers, after all, and are not meant to be viewed as an absolute indicator of someone's playing strength. I've long held the opinion that the values should carry a confidence interval of ±10, and this fits the numbers above rather well.

1 comment:

  1. Ok pinch of salt seems a bit harsh, but yes given that the clubs/leagues for whatever reason do not seem capable of submitting the requisite information in a timely fashion, and some of the nuances mentioned in previous articles, your suggestion that a confidence interval of +/-10 would seem a useful concept for us all. Thus when we are playing anybody unknown with an official grade we should effectively allow a 20 point variance! To summarize, I don't necessarily think the system per se is necessarily bad, but all club officials need to ensure that all qualifying games be submitted at correct times.

    Good article Mark