Blue Horizon Chess Blog - The Life of a Chess Novice » Grading

New Grades Published…

Dave — Mon, 21 Jul 2008 18:49:33 +0000

I’ve gone from ECF 83 to ECF 94.

http://grading.bcfservices.org.uk/getref.php?ref=261619B

Not too bad an improvement over the year.

Are ECF Grades Deflating?

Dave — Wed, 11 Jun 2008 17:44:26 +0000

My next grading goal is to break through the 100 ECF barrier, but it would seem that my grade of 83 is somewhat deflated and actually I should be there already!

From what they are saying over at the Streatham & Brixton blog, next season I will have two grades, the official one (probably about 95) and an unofficial corrected one (about 125). The season after that the corrected grade will be the one used.

Confused?

Apparently the grades have been suffering from deflation over several years. Having no idea what a 100 ECF grade player was like 20 years ago I can’t personally give an opinion as how now and then would compare, but some seem to think it’s the ECF handing out an ego boost to those whose grades have slipped rather than a deflation correction.

It makes you wonder what the ECF would have done if the grades had been inflated – I seriously doubt they would have lowered them as that would have demoralised many players, causing them to abandon league chess in their droves. However, as they are in the process of messing with the grades I can’t see why they didn’t just take the opportunity to switch over to the Elo system.

Whatever happens, looks like I’ll make 100 ECF by Summer 2009!

New ECF to Elo Conversion Formula

Dave — Thu, 05 Jun 2008 17:46:58 +0000

I’ve done some statistical analysis on players with both ECF and FIDE Elo grades and decided that the ECF formula for converting to Elo could use some work.

I propose that the new formula should be:

Elo = (ECF x 6.14) + 1050

This gives an R2 fit of 0.946 against the plotted data. The graph below shows my model (black line) vs the ECF model (red line).

I’ll give more details in a future post.

ECF Grading – Statistical Distribution

Dave — Mon, 31 Mar 2008 13:11:53 +0000

I’m a bit of a stats freak! Long lists of numbers give me the urge to do some analysis and put them into some sort of context we can all understand. I’m graded 83 ECF – but what does that mean in the greater scheme of things. On it’s own it means nothing, but in the context of the entire ECF grading database it shows what I expected – I’ve got a long way to go!

Having downloaded the entire ECF database which includes virtually all club and tournament players in the UK, I created a histogram of standard play grades (a total of 10376 players) using a bin width of 5 – click on the image below to view the chart.

This allows us to break down all UK club/tournament players into percentiles:

25th percentile – 82 (1660 Elo*)
50th percentile – 110 (1800 Elo)
75th percentile – 140 (1950 Elo)
90th percentile – 168 (2090 Elo)
95th percentile – 185 (2175 Elo)
99th percentile – 228 (2424 Elo)

So, based on this, my grade of 83 means that I’m just over the 25th percentile, which means I’m stronger than 25% of UK club players.

The most common grade is 117 ECF and the average player is rated with a grade of 110 (50th percentile). A top 10% club player is graded over 168. To break into the UK Top 100 you will need to be graded at least 229!

However, this only accounts for players who are serious enough to play for a club or in tournaments and obtain a rating. It is estimated that about 5 million people in the UK play chess (even if only casually), leaving around 50 million non-chess players (if we discount very young children). I’m making a fairly big assumption here, but I’m assuming that all non-chess players will be weaker than any chess player – meaning that a chess player will automatically be stronger than the other 90% of the population.

Based on those figures, I am now stronger than 92.5% of the UK population – that sounds a lot better than 25%!

—

* The FIDE Elo / ECF conversion is calculated using standard formulae given by the British Chess Federation:
215 ECF and below : Elo = ( ECF * 5 ) + 1250
216 ECF and over : Elo = ( ECF * 8 ) + 600