>i searched in the web, i admit I didnt understand almost anything.
>i was told that the official ranking system is the one used on FIBS server
>and that an experience player doesnt have any weight after 400 games, is it
>true?
Basically, the FIBS formula calculates your rating change based on the
length of the match and the difference in ratings between the two
players. Even though the math looks scary, it's very straightforward.
As a special case, players who have less than 400 points of experience
get bigger ratings swings... the general idea is to help you find your
"true" rating more quickly. But <400 is really a special case of the
fairly simple general formula.
So it's not that the player has no influence over 400 points, it's
just that the extra newbie skew goes away at 400.
>last but not least: how do u calculate a rating change in double
>consultation tournaments?
I assume you mean doubles tournaments, where two players consult over
each move? Personally, I wouldn't count these at all.
-Patti
--
Patti Beadles, Oakland, CA |
pat...@gammon.com | Thinking about you as innocent
http://www.gammon.com/ | is sort of like thinking about
Check out www.tribe.net! | a viking playing badminton.
She has already developed ranking systems for both knockout and swiss
formats using excel.
Hope she can help...
Andrew
"fiore" <fiore_...@galactica.it> wrote in message
news:On6Eb.790$Jw2...@tornado.fastwebnet.it...
She has already developed ranking systems for both knockout and swiss
formats using excel.
Hope she can help...
Andrew
"fiore" <fiore_...@galactica.it> wrote in message
news:On6Eb.790$Jw2...@tornado.fastwebnet.it...
Michael - who always does his own posts! :-)))
PLEASE NOTE:
Due to the overwhelming amount of spam received at this email address, only
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will be deleted from my server.
"Elizabeth Barker" <eb006...@blueyonder.co.uk> wrote in message
news:_u8Eb.36310$5F2....@news-binary.blueyonder.co.uk...
>How is this mysterious simple one?
Here is what you get when you ask FIBS for it's rating formula:
> help formula
NAME
formula - The formulas used to calculate rating changes
DESCRIPTION
These are the formulas used to determine the ratings of a player:
Let's say that two players P1 and P2 were playing a n-point match.
The ratings of the players are r1 for P1 and r2 for P2 .
Let D = abs(r1-r2) (rating difference)
Let P_upset = 1/(10^(D*sqrt(n)/2000)+1) (probability that underdog wins)
Let P=1-P_upset if the underdog wins and P=P_upset if the favorite wins.
For the winner:
Let K = max ( 1 , -experience/100+5 )
The rating change is: 4*K*sqrt(n)*P
For the loser:
Let K = max ( 1 , -experience/100+5 )
The rating change is: -4*K*sqrt(n)*P
The 'experience' of a player is the sum of the lengths of all matches
a player has finished. Every player starts with a rating of 1500 and
an experience of 0.
SEE ALSO
ratings
>
Let's walk through this in English.
D is the difference in the two ratings. If you're rated 1850 and I'm
rated 1750, then D=100. Easy enough.
n is the match length. The real workhorse of the formula is in the
P_upset line; that calculates the probability of the lower-ranked
player winning the match.
P then becomes P_upset if the lower-rated player wins, or 1 - P_upset
if the higher-rated player wins.
K is the factor that scales for people with lower experience. Once
a player hits 400 experience, K is always 1.
So essentially, the winner get 4 * the square root of the match
length * the probability of his winning, and the loser loses that
much.
-Patti
--
Patti Beadles, Oakland, CA |
pat...@gammon.com | Going to war over religion is
http://www.gammon.com/ | basically arguing over who has the
Check out www.tribe.net! | better imaginary friend.