Rating formula


Rating formula

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Heinz-Georg Lehnhoff    (2006-06-14)
Rating formula

Hello Thibault!

Where can I found the exact rating rules of FICGS? I have found only these lines in the Memberships - Terms and Conditions:

"11. 7. Rating rules

The FICGS rating scheme is a numerical scheme, in which percentage results can be exchanged into rating differences, and rating differences into percentage performance probabilities. It is mainly based on the principles of rating calculations of prof. Arpad Elo.

The rating formula : New Elo = ((16 x Elo) + (Games x Perf)) / (16 + Games) ..."

What means "mainly based"?

You write in another topic

"1. The rating system do not take account of wins when the ELO difference is superior to 350 points "

Is this valid only for wins or for all games with a rating difference of more than 350 points?

Thibault de Vassal    (2006-06-14 19:21:53)
Elo rating calculation

I just updated the membership page, with the full rating calculation explained.

It is exactly the rules used by the french federation, except the special rule that makes it easier to win than to loose points (and partly provokes Elo inflation). So only one formula is used here.

Heinz-Georg Lehnhoff    (2006-06-16 11:35:05)
Elo rating calculation

Hello Thibault!

How are provisional ratings are treated?

Two notes to the rules:
1. You write: "Bonus is given by the Percentage (100 * Points / Games) obtained" and "If the percentage is negative, ..." Percentage cannot be negative. I think you mean: If percentage < 50
2. You write "Please note that Bonus is limited to 470 points". Why do you write other values for 96-99 % in the Bonus-Table?

Thibault de Vassal    (2006-06-16 13:46:10)

Hello Heinz-Georg.

Thanks for help :) Indeed, I've forgotten the parameter for provisional ratings (that evolve quicker than established ratings)... I'll change these points within hours. (right, 95 to 99 values in the bonus table are useless, but it is informative about the formula)

Wayne Lowrance    (2006-06-17 07:36:58)
rating calc

Welp, I am another innocent victim of starting off at 1400. When I signed on I wanted to start at the beginning, much like daniel. what I really did not pay attention to is the difficulty in climbing the ladder. My chess rating on other sites including CC cite is well over 2200. I started there at the bottom and figured I would do the same here. Not so fast. I have won one tourney here weith 6/6 score tourney allready and am have a perfect scored in a second one with 3 games to go. and yet my expected rating is listed at 1805, cleary I am not a 1800 player. It is not my fault that I was forced to play in a tourney dominated by 1400 players. What you think. Not trying to cause trouble, just venting I guess. and the cite is nice, will continue playing, my best toya Wayne p.s. do you think my playing in a 1400 tourney is fair to those players, hummm?

Thibault de Vassal    (2006-06-17 12:39:45)
Correspondence chess

Hello Wayne.

Correspondence chess is definitely a game of patience...

Note : When you register, you can enter your rating ! The rules state a rating not from FIDE / IECG / ICCF gives at most a 1700 rating... So you could have started with a 1700 rating ! Anyway in july (after the next rating calculation) you can play stronger tournaments... and so on..

Wayne Lowrance    (2006-06-17 19:02:07)
Rating formula

Okey Dokey, I understand. Wayne

Heinz-Georg Lehnhoff    (2006-07-12 20:12:40)
Tournament entry rating

Hello Thibault!

Am I right that my TER (tournament entry rating) is not essential for the calculation of my new FIGCS - ELO - rating. If I'm not right, in which variable can I find it? I thought the difference of my opponents and my own rating at the beginning of the tournament would be of importance.

Thibault de Vassal    (2006-07-12 22:54:50)
Tournament entry rating

Hello Heinz-Georg.

Your TER is not taken in account when a rating calculation occurs (your opponent's one is, of course).

But your previous ELO has a weight in the formula...

Eric Berthelot    (2006-07-21 09:59:50)
Mise jour classement ELO

Thibault, peux-tu me dire quand sont mis jour les ELO ?

Thibault de Vassal    (2006-07-21 11:24:02)
Mise a jour classement ELO

Bonjour Eric.

Tout est l (11.7) : http://www.ficgs.com/membership.html#general

"The rating period is 2 months. The first period of a year starts on January 1st. For ratings calculations, the opponents' Tournament Entry Rating (TER), which are valid on the day of the rating run, are used."

La prochaine mise jour sera donc pour le 1er septembre.