Tuesday, June 10, 2008
Great News for Chess Grades?
-- Or -- Putting the Grrrrrr into Grading?
-- Or --Putting the Grrrrrr into Grading?
Posted by Tom Chivers
You know how your grade is calculated, right? If you beat a player, then into your average for the next year goes their grade plus fifty; if you draw, just their grade; if you lose, their grade minus fifty: and then all your results are averaged. Of course there's also the forty-point rule - this deals with results between players separated by more than forty points in order to make illogicalities like losing grading points from victories impossible. And of course if you don't play thirty games in your season, then some of your previous results go into to your average as well, until it tots up to thirty, if possible. And that's it, right? How it always has been, how it always will be, grade after grade, list after list, season after season, decade after decade? Right?
WRONG! Because next year, you'll have two grades. The first will be your normal grade, calculated as above. That will be your official grade for the season. The second will be your corrected grade, which is (approximately) your normal grade multiplied by 0.8, with 50 added on to it. But as of 2009-10, this corrected grade will form the basis of all new gradings.
Then read on. All will be revealed, as best I can . . .
So, here's the story. A little while back the English Chess Federation (ECF) commissioned research into whether or not their grading system suffered inflation or deflation. The statisticians who worked on this concluded that the lower the grade, the more deflated it was. After queries, double-checking, and much discussion, the ECF and their statistics team then worked out a formula to correct the deflation. That's the formula I gave above, approximately. As to the reason why the corrected grades are visible this year - but will be only be operationalized next year - that's simple. This way tournament controllers and league secretaries and the like can work out what their new grading boundaries will have to be next year - with a whole year to study the new corrected gradings and their implications. In other words, we'll all have a whole year to get used to this new lay of the land.
So, what does it mean? Well, if your grade next year is 100, your corrected grade will be 130 - a thirty point jump. But if your grade next year is 200, your corrected will be 210 - only a ten point jump. That's because the lower the grade, the more deflated. In fact if your grade next year is 250, then your corrected grade will still be exactly 250.
Now personally speaking, I'm no statistician, and I'm not going to argue with the experts on this, nor pretend I can refute all their research from my desk. In fact, my personal experience tends to confirm this kind of thing. My average grade this year against players rated lower than me is 22 points lower than my average grade against players rated higher than me. This confirms what the ECF says. And I remember more than a decade ago watching a game between two players rated in the 120s that started 1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 Nc6 6. Bd3?? Nxd4, after which white went on to win in about twenty more moves - without having batted an eyelid at his knight that had dropped off the board on move 6, let alone it seemed having contemplated resignation over it. But nowadays, I can't remember the last time I saw a 100 graded player make so crass a blunder. I've played several players around that grading level this year, and I consider them all decent club players. In fact two of them drew against me, and a third should have. Finally, on a personal note, I've heard several experienced and strong players - players whose opinion I respect far more than my own - say they think grades are increasingly deflated.
But not everybody is so convinced. Tim Spanton is arguing on the ECF forum, in fact, that a lot of people he knows believe the ECF are doing this for a different reason. "The suspicion," he writes, "is that this is a gimmick to raise grades for no reason other than stroking the fragile egos of people who can't stand seeing their grades going down (and aren't prepared to put in the hard work necessary to reverse such a process)." Well, what do you think? That this is a great move for grading? Or unnecessary meddling - just the ECF putting the Grrrrrrr into Grading?
(And, by the way, if you feel like joining in the debate over at the ECF, then their grading forum can be found by clicking here.)
at 10:01 am