ECF Grading – Statistical Distribution
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
Thursday, May 29th 2008 at 12:25 pm
Is a grading system rather than elo better for club chess. I’m not too bright at maths so you’d have to explain why it might be better/worse.
Would a grading system be better than elo on an internet chess site. Again if so why? Elo seems a good general measure but in a clearly defined context the idea of grading seems better. Or is there no real difference…remeber if you answer: I’m thick!
[Both Elo and ECF are grading systems, just that the formula used in each case is somewhat different. Which is better is rather subjective, ECF is easier to work out, but Elo perhaps gives a better distribution. - Dave]
Thursday, June 5th 2008 at 9:58 am
I would really like a copy of this diagram to compare to the USCF graph I already have. I don’t agree with the current formula’s to convert ECF to FIDE
Monday, July 28th 2008 at 4:20 pm
Dave
I never really realised just how “lefthanded” the distribution is before.
When you say “This allows us to break down all UK club/tournament players into percentiles” be careful. The ECF grading list includes all players who’ve played in graded events, including non-UK players. For example, only one of the top 10 players (Adams) is English, the rest have simply played in the UK in the last year but are definitely not UK players.
Just having a quick look at the top I’d say that to get into the top 100 you probably need a grade of about 209-210.
I’m sure the grades for all your percentiles should be a bit lower than you show, so you’re probably a couple of percentage points better than your own calculations!
Saturday, December 20th 2008 at 5:55 pm
The distribution is “left-handed” because of the existence of large sub-pool, that of juniors. Most of these are rubbish and won’t improve and will eventually drop out of the list, out of lack of interest; some though are not rubbish, but have lowish grades, and those grades will move into their proper places on the right hand of the distribution as they play (and gain points from) adults.