Exeter Chess Club: BCF-ELO chess grade conversion

BCF-ELO chess grade conversion: (c) cbcm 1993

ELO=(BCF*8)+600: 1 BCF point = 8 ELO points

N.B. USCF and ELO have the same form but I believe USCF ratings run a little higher than ELO: say, about 100 points on average. The data in the third to fifth columns is from Prof. Elo's book on The Ratings of chessplayers, past and present., although comparability between national systems is both difficult and occasionally controversial. See below for my attempt.

The tables below are a bit of bodge numerically and in terms of HTML; they should be readable by text-only browsers like LYNX and graphical ones like Netscape; I try to avoid "enhancements" but Tables is good standard HTML.


BCF ELO
70 = 1160
75 = 1200
80 = 1240
85 = 1280
90 = 1320
95 = 1360
100 = 1400
105 = 1440
110 = 1480
115 = 1520
120 = 1560
125 = 1600
130 = 1640
135 = 1680
140 = 1720
145 = 1760
150 = 1800
155 = 1840
160 = 1880
165 = 1920
170 = 1960
175 = 2000
180 = 2040
185 = 2080
190 = 2120
195 = 2160
200 = 2200
205 = 2240
210 = 2280
215 = 2320
220 = 2360
225 = 2400
230 = 2440
235 = 2480
240 = 2520
245 = 2560
250 = 2600
255 = 2640
260 = 2680
265 = 2720
270 = 2760
[cool blue cat says:] generated by
A Cool Blue Cat c programme

Calculation of grades and ratings

BCF grades are pretty easy to calculate: you score for each graded game the current grade of your opponent if you draw, that grade +50 if you win, -50 if you lose (unless the grade difference is so great you might lose points for winning, in which case you assume the grades are 40 points apart and you score +10).

ELO ratings are more sophisticated, and are based on statisticians' Normal Curve. Assume that the "class interval" (bottom of category A to bottom of category B) is 200 rating points. The distribution of scores of a player against someone their own strength is expected to fit the normal curve (upper graph) and the expected result against a player different to their rating by "x" class intervals follows the normal distribution function (lower graph).

Working out exact ELO scores from statistics tables (or using computers) is possible but not very practical. Fortunately the middle part of the function +- 1.5 class intervals is more or less straight and so you can pretend that it is straight for most purposes (a.k.a 'linear approximation').

So, to work out your rating performance in the ELO system, you can take the average rating of your opposition, work out your expected score, look at your actual score, and see how your rating should be adjusted. [There are some fiddles to cope with new players, but that's the gist of it.]

I was going to launch into the rest but both Arpad Elo and Joe Brooks have put it better than I could (but note that Joe's account has in mind the US context), and of course it is covered in the wonderful FAQ.

Glicko Ratings as implemented on the Free Internet Chess Servers (FICS) contain the fiddles for new players built in to the formulae used, so the same formula can be used by the computer for all players. This is a superb refinement to the ELO system but not readily implemented for pencil-and-paper tournaments.


Player classes and titles

Most GMs amd IMs come in the 'class' ELO 2400-2600. When Elo wrote, he regarded 2600 as 'World Championship Contenders', although now the term Super-GM is used in magazines (at least in the UK).

The figure that ELo took as the top of "strong amateurs" was 2000 (BCF 175), although clearly many strong amateurs are better than that. The 'magic figure' in this country always seems to me to be 200 BCF (2200 ELO), as you will discover by talking to any UK player whose highest-ever grade is 199. It's the chess four-minute mile here, although you don't get called a master by reaching it.

LEVEL BCF grades ELO USCF class Eastern European category
{D} Minor BCF 80-100 ELO 1240-1400 D category 4
{C} Intermediate BCF 100-120 ELO 1400-1560 C category 3
{B} Major BCF 120-150 ELO 1560-1800 B category 2
{A} County BCF 150-180 ELO 1800-2040 A category 1
Top county players BCF 180-200 ELO 2000-2200 Expert: USCF 2000-2199 candidate master
ELO 2200-2300 US National Master: USCF 2200-2399 National Master
ELO 2300-2400 US Senior Master USCF 2400+National Master
International Master BCF 220-240 ELO 2360-2520
Grandmaster BCF 240-250 ELO 2520-2600
Super-GM BCF 250-270 ELO 2600-2700+


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This document (bcftable.html) was last modified on 17th Sep 96 by

Dr. Dave