View Full Version : ACF Ratings Observation

Max Illingworth
20-12-2010, 02:57 PM
In the December 2010 rating period for ACF ratings, I note that of the fifteen players rated over ACF 2200 who played in a rated tournament in this rating period, 12 lost rating points. Other than the top 5 players in the country on ACF ratings, players who did not play a tournament rated in the December 2010 ACF ratings increased their ranking relative to the September 2010 ACF rating list.

Here are the rating changes of players rated over 2200 on the September 2010 rating list:

Zong-Yuan Zhao: from 2580 to 2579. 0 games played.
David Smerdon: from 2489 to 2488. 0 games played.
George Xie: from 2461 to 2463. 7 games played.
Alex Wohl: from 2415 to 2414. 0 games played.
Darryl Johansen: 2362 to 2362. 0 games played.
Stephen Solomon: 2335 to 2315. 15 games played.
Igor Bjelobrk: 2329 to 2291. 7 games played.
Jesse Sales: 2327 to 2326. 0 games played.
Igor Goldenberg: 2326 to 2306. 6 games played.
Junta Ikeda: 2320 to 2238. 16 games played.
Gary Lane: 2320 to 2319. 0 games played.
Greg Canfell: 2316 to 2229. 18 games played.
Tomek Rej: 2299 to 2298. 0 games played.
Moulthun Ly: 2298 to 2288. 15 games played.
Samuel Chow: 2294 to 2293. 0 games played.
Guy West: 2286 to 2283. 16 games played.
Vincent Suttor: Originally 2286, drops off top players list (presumably due to inactivity).
Vladimir Smirnov. 2280 to 2273. 41 games played.
Mark Chapman: 2274 to 2272. 0 games played.
Peter Froehlich: 2271 to 2270. 0 games played.
Michael Baron: Originally 2266, drops off top players list.
Geoffrey Saw: Originally 2262, drops off top players list.
Tristan Boyd: 2261 to 2261. 0 games played.
Bobby Cheng: 2227 to 2207. 38 games played.
Mirko Rujevic: 2225 to 2224. 20 games played.
Christopher Wallis: 2219 to 2232. 14 games played.
James Morris: 2203 to 2190. 21 games played.
Leonid Sandler: 2203 to 2213. 4 games played.
Dusan Stojic: 2201 to 2173. 24 games played.

Two players who were absent from the September 2010 Top Ratings list, Erik Teichmann and Max Illingworth, entered the December 2010 rating list with ratings of 2312 and 2284 respectively. Endre Ambrus was on the previous ‘Top Players’ list and joined the group of players with reliable ratings over 2200 with a rating increase from 2185 to 2221, playing five games in the rating period.

If the trend from the September rating list to the December rating list is sustained, it would suggest that the ACF ratings are in a state of deflation at the top. Of course, it is quite possible that this is a one-off instance of ratings deflating at the top.

Another hypothesis is that players rated below 2200 are catching up to the over 2200 players in playing strength. However I doubt this given that Ambrus was the only player to increase his rating from below 2200 to over 2200 on the December 2010 rating list.

This is in no way intended as a criticism of the ACF ratings. In any instance, I am interested to hear your views on this observation.


Kevin Bonham
20-12-2010, 04:30 PM
A single ratings period rarely proves anything but it would be well worth having a look at:

* the number of active 2300+ players over time and the causes of loss of players from that group
* comparative trends for FIDE ratings (note that this has to be treated with some care as FIDE ratings have been increasing at the top)

Barry's web site download section at http://www.bjcox.com/modules.php?name=Downloads&d_op=viewdownload&cid=1 has ACF ratings lists back to 1998.

Kevin Bonham
20-12-2010, 07:38 PM
Just quoting this from shoutbox so Viewed sees it

[20-12-2010 07:06 PM] Viewed: Kevin, it is possible to sort or download the old acf master lists in rating order?
[20-12-2010 07:07 PM] Viewed: is it*
[20-12-2010 07:58 PM] Kevin Bonham: you'd have to find some way to paste them into excel then sort by rating order
[20-12-2010 07:58 PM] Kevin Bonham: that means pasting into excel by columns. my memory is it works sometimes but not always as some come through in funny formats
[20-12-2010 07:59 PM] Kevin Bonham: in excel Paste As: Unicode Text is often (but not always) handy for pasting things in order
[20-12-2010 07:59 PM] Kevin Bonham: old threads here are useful for seeing top rated players but only back to 2004
[20-12-2010 08:07 PM] pappubahry: Save the text file as .txt, then open from Excel, and choose 'fixed width'.
[20-12-2010 08:07 PM] pappubahry: There'll be a little preview where you can drag the column separators.
[20-12-2010 08:30 PM] ElevatorEscapee: I've done this myself in the past successfully by using a method similar to the one suggested by pappubahary.
[20-12-2010 08:33 PM] ElevatorEscapee: I'm happy to give more detailed instructions (pappa forgot to mention the "text to columns" option between 'save as Excel' and 'choose fixed width') ;-)