Search found 434 matches

by Brian Valentine
Tue Aug 18, 2009 3:17 pm
Forum: Grading Debate
Topic: When is the new grading list coming out?
Replies: 509
Views: 34800

Re: When is the new grading list coming out?

Roger, You are right, I don't know where I lost the thread, but will have to rethink my position on overseas influence. And I might end up agreeing with Ola. It's difficult to draw the line on domestic and overseas; I took the view that many of the "blanks" would not regard themselves as English and...
by Brian Valentine
Tue Aug 18, 2009 1:00 pm
Forum: Grading Debate
Topic: When is the new grading list coming out?
Replies: 509
Views: 34800

Re: When is the new grading list coming out?

If have defined overseas players as those who are not Blank, England, Ireland, Wales or Scotland. There are 529 of them listed of which 334 have a grade in 2008 and 403 in 2009. There average grade for both years is in the mid 190s. There is not enough data to work out what effect they may have, as ...
by Brian Valentine
Mon Aug 17, 2009 7:23 pm
Forum: Grading Debate
Topic: When is the new grading list coming out?
Replies: 509
Views: 34800

Re: When is the new grading list coming out?

I was trying to highlight the effect of leaversand joiners being an ongoing issue to control and probably more important than the points transfers from active versus relatively inactive (which may be a problem. I accept these bald statistics can be mis interpreted but I can't see a way of digging in...
by Brian Valentine
Mon Aug 17, 2009 3:45 pm
Forum: Grading Debate
Topic: When is the new grading list coming out?
Replies: 509
Views: 34800

Re: When is the new grading list coming out?

It isa complete fluke if the system comes out as zero sum. It depends on the relative grades of leavers and joiners. Here is an analysis of last year's movements. The 2008 list I refer to is the 2008 grades posted in 2009 or, if missing, the red grade from the 2008 list 2008 list: 10257 entries at a...
by Brian Valentine
Sun Aug 16, 2009 9:21 am
Forum: Grading Debate
Topic: When is the new grading list coming out?
Replies: 509
Views: 34800

Re: When is the new grading list coming out?

Here are a few statistics that tend tosupport recent comments here: These are the average movement in grades by categories for juniors. So 2008 Category E who became category A in 2009 improved 19.6 points - Thereare only 13 players in this group [img] 2009 A B C D E 2008 A 10.4 5.2 6.8 - 5.3 3.3 B ...
by Brian Valentine
Sat Aug 15, 2009 8:39 am
Forum: Grading Debate
Topic: When is the new grading list coming out?
Replies: 509
Views: 34800

Re: When is the new grading list coming out?

The recursion approach clearly smells rotten. Before deciding on the fix, I am attempting to develop the ground rules. At the risk claiming to be more fundamental, here are some strands from various threads and analysis of the rating lists: -The problems highlighted arise mainly from juniors -Severa...
by Brian Valentine
Fri Aug 14, 2009 10:23 pm
Forum: Grading Debate
Topic: When is the new grading list coming out?
Replies: 509
Views: 34800

Re: When is the new grading list coming out?

Most of the discussion on this thread has been about the approach to grading Juniors, but the main item for system change was to eliminate stretch. Clearly the recursion approach adds to stretch and not enough data is available to investigate the contribution to the system of this approach. If the g...
by Brian Valentine
Tue Aug 11, 2009 10:08 pm
Forum: Grading Debate
Topic: When is the new grading list coming out?
Replies: 509
Views: 34800

Re: When is the new grading list coming out?

It should also be noted that juniors are now treated as ungraded players. This dashes any hopes that any adult has of securing a massive increase in grade by spotting an 'obviously overgraded junior' playing a 30 game against them. If both players score at least 3 points, and those are the only 30 ...
by Brian Valentine
Wed Aug 05, 2009 10:22 am
Forum: General Chat
Topic: when should you resign a game?
Replies: 54
Views: 4917

Re: when should you resign a game?

My position on this issue is similar but with a nuance. I will resign when it is clear that my opponent knows how to win the game. (However if I allow them to start a short forced mating sequence I will let them complete it).
by Brian Valentine
Mon Aug 03, 2009 5:49 pm
Forum: Grading Debate
Topic: Inflation in the international system
Replies: 12
Views: 2456

Re: Inflation in the international system

I would just like to point out that my analysis was based on the premis that the system was functioning correctly. Even in that situation stretch exists. I am more aware of the impurities in the system, because of the debates that are taking place here. These impurities will all contribute to stretc...
by Brian Valentine
Thu Jun 11, 2009 4:02 pm
Forum: Grading Debate
Topic: amateur hour in the 4NCL FIDE grading.
Replies: 42
Views: 5557

Re: amateur hour in the 4NCL FIDE grading.

Sean,
Thanks for providing the link and spending time auditing the entries. One up to the administators. Just don't use my grades to fit an ECF to elo conversion table - they continue to diverge!
by Brian Valentine
Thu Jun 11, 2009 1:24 pm
Forum: Grading Debate
Topic: amateur hour in the 4NCL FIDE grading.
Replies: 42
Views: 5557

Re: amateur hour in the 4NCL FIDE grading.

I have just looked up my FIDE July 2009 calculations and there are games missing against players with long established ratings. Frustratingly only my defeats are recognised. I don't know if this is related to the issues above (I don't think so). Usually 4NCL publish a spreadsheet to show what has be...
by Brian Valentine
Wed Jun 10, 2009 3:19 pm
Forum: Grading Debate
Topic: GRADING ANOMALIES
Replies: 565
Views: 74411

Re: GRADING ANOMALIES

Robert, You are barking up the wrong tree on this. For one, your unrealistic assumption of a two player match hides the fact that normally the factor is 1/n where is based on games included in the next list. For two, the system is trying to rank players as though their strength is not changing much....
by Brian Valentine
Tue Jun 09, 2009 9:43 pm
Forum: Grading Debate
Topic: GRADING ANOMALIES
Replies: 565
Views: 74411

Re: GRADING ANOMALIES

Let us assume that two players both with grade of 100 play a match of 30 games during a course of a season and that one of the players scores 80%. Then, it follows (from the relationships 'p = f(d)') that (at the end of the season) one of the players should be regarded stronger (than the other) for...
by Brian Valentine
Tue Jun 09, 2009 7:59 pm
Forum: Grading Debate
Topic: GRADING ANOMALIES
Replies: 565
Views: 74411

Re: GRADING ANOMALIES

Mathematically, a system stretches the grades if 'ka + kb > 1', and since for current grading system it holds that 'ka + kb = 2', it stretches the grades for '|p - q|' (which is "a lot"). Non-mathematically, evidence of stretching is shown in the example you have mentioned in point 3 below, where t...