Search found 387 matches

by Chris Goodall
Thu Oct 24, 2019 11:04 pm
Forum: Grading Debate
Topic: ECF Grading Proposals
Replies: 210
Views: 15463

Re: ECF Grading Proposals

Thanks for that paper. Maybe it was a real problem. I do wonder how on earth they expected the change to stick. If someone is playing at a grade X vs a roughly stable field and you differentially uprate all their weaker opponents, they'll inevitably directly benefit from that. The same reason Briti...
by Chris Goodall
Thu Oct 24, 2019 5:34 pm
Forum: Grading Debate
Topic: Don't Understand Grading Calculation
Replies: 32
Views: 1723

Re: Don't Understand Grading Calculation

Roger de Coverly wrote:
Thu Oct 24, 2019 2:03 pm
The underlying mathematical statistics of both systems makes an assumption that chess strength is stable if unknown. Arguably an assumption that breaks if you try to apply it to extremely weak players.
When you say stable, are you talking low stdev that can drift, or high stdev with a stable mean?
by Chris Goodall
Thu Oct 24, 2019 12:39 pm
Forum: Grading Debate
Topic: ECF Grading Proposals
Replies: 210
Views: 15463

Re: ECF Grading Proposals

For instance in 2009 3.9% were graded above 200 whereas 6.6% are now. The effect of having more of the world's top players taking part in domestic graded events presumably influences this. Gibraltar, the London Classic and Isle of Man for example. The recent Grand Swiss brings even more of the top ...
by Chris Goodall
Thu Oct 24, 2019 12:13 pm
Forum: Grading Debate
Topic: Don't Understand Grading Calculation
Replies: 32
Views: 1723

Re: Don't Understand Grading Calculation

Isn't this what used to happen before the central computer program took over the job of working out what a new player's grade should be? (Except there was then no iteration because there was no program.) Local graders' estimates were usually accurate to within 10 points or so, I recall. They could ...
by Chris Goodall
Wed Oct 23, 2019 3:41 pm
Forum: Grading Debate
Topic: Don't Understand Grading Calculation
Replies: 32
Views: 1723

Re: Don't Understand Grading Calculation

A player walks into your club and claims to be from a country you were sure was still part of Russia. You put him on board 5 in Division 3, and he easily beats a couple of children graded 38 and 49. Do you therefore let him enter the Under 100 section of your congress, because the fact that he play...
by Chris Goodall
Wed Oct 23, 2019 2:47 pm
Forum: Grading Debate
Topic: Don't Understand Grading Calculation
Replies: 32
Views: 1723

Re: Don't Understand Grading Calculation

Isn't Martin suggesting that the player moves up to say 90th percentile when they start the game with the locational extra information and they drop to 73 when the additional information of the result becomes available? So the fact that they found themself sitting opposite a certain person is 40 pe...
by Chris Goodall
Tue Oct 22, 2019 10:23 pm
Forum: Grading Debate
Topic: ECF Grading Proposals
Replies: 210
Views: 15463

Re: ECF Grading Proposals

4. Will a player be able to ask the ECF to delete a historic grade more than 'n' years old so that he can start afresh? 4. This is not something we envisage. Organisers want the evidence for section limits. That's a good reason to delete historic grades of players who were last active before 2009, ...
by Chris Goodall
Tue Oct 22, 2019 11:29 am
Forum: Grading Debate
Topic: Don't Understand Grading Calculation
Replies: 32
Views: 1723

Re: Don't Understand Grading Calculation

Well what happens in league chess is that they play a few stronger people, you get a decent estimate and they're stuck on a realistic (if often slightly conservative) board. The strength of their teammates on either side is arguably more useful data than their opposition but using that would be sli...
by Chris Goodall
Mon Oct 21, 2019 4:16 pm
Forum: ECF Matters
Topic: Women's Recruitment Officer
Replies: 17
Views: 2352

Re: Women's Recruitment Officer

While I must congratulate Tim on his appointment, surely it is a sad state of affairs that ECF was not able to appoint a woman to the role of Women's Recruitment Officer? Why? Is there a smaller, pinker and more expensive Women's ECF that only women are allowed to grant membership of? Do we have to...
by Chris Goodall
Mon Oct 21, 2019 10:02 am
Forum: Grading Debate
Topic: Don't Understand Grading Calculation
Replies: 32
Views: 1723

Re: Don't Understand Grading Calculation

I would ask the 200 how well his opponent played and provide an informal estimate of grade. Then you have to know whether the 200 is the kind who thinks every game they win a Herculean effort worthy of a candidates' tournament, or the kind who assigns everyone below 195 to the same "idiot" category.
by Chris Goodall
Mon Oct 21, 2019 9:23 am
Forum: Grading Debate
Topic: Don't Understand Grading Calculation
Replies: 32
Views: 1723

Re: Don't Understand Grading Calculation

I don't agree; I think the flaw in the logic is that it does not regard as significant the fact that this unknown X has played a game against a player graded 200 (which is *already* information about their strength, even prior to the result). i.e. the average grade among players who have played a g...
by Chris Goodall
Sun Oct 20, 2019 11:09 pm
Forum: Grading Debate
Topic: Don't Understand Grading Calculation
Replies: 32
Views: 1723

Re: Don't Understand Grading Calculation

Hummm, I'm not sure you know. I think team captains tend to have a decent idea how strong players are, and that determines the strength of the field they play to a fair extent. Also people entering the 'right' part of Open tournaments. Seems like information to me. Weak, but information. Not got an...
by Chris Goodall
Sun Oct 20, 2019 8:35 pm
Forum: Grading Debate
Topic: Don't Understand Grading Calculation
Replies: 32
Views: 1723

Re: Don't Understand Grading Calculation

I also think that all grading/rating systems struggle with 100 (or 0!) % scores. They don't have to. It's a German Tank Problem . If you capture a single tank, and its serial number is 60, estimate how many tanks have been manufactured? Since you only have one data point, the best assumption you ca...
by Chris Goodall
Sat Oct 19, 2019 1:32 am
Forum: General Chat
Topic: Chess and Pension Fraud - allegation
Replies: 60
Views: 12003

Re: Chess and Pension Fraud - allegation

Well, if people will try to commercialise an amateur game that no-one is interested in paying to watch, they'll end up presenting the Arthur Daley Trophy to the winner of the TrotterBrothers.com Open.
by Chris Goodall
Thu Oct 17, 2019 6:50 pm
Forum: ECF Matters
Topic: Complaint to ECF Board about CEO Mike Truran re. Development Officer appointment
Replies: 118
Views: 11545

Re: Complaint to ECF Board about CEO Mike Truran re. Development Officer appointment

It's a downside of the perks of having a charity as part of your financial structure that you mostly lose control of the money in the charity. Similar problems have arisen from time to time with the John Robinson Trust where the ECF and the Trustees haven't seen eye to eye on what needed financing....