ELO Ratings

It has been proposed by Yaron Racah that ELO ratings be generated for Firetop Mountain users. In addition to being of general interest ratings could be used to restrict 'Open' challenges to opponents with ratings in a certain range.

I found the following formula for calculating ELO

Bonus = K * (V - 1 / [1 + 10**((EloOpp - EloOld) / 400)])

where
EloOld = Your elo
EloOpp = Elo of your opponent
V = (1 for a win, 0.5 for a draw, 0 for a loss)
K is the development coefficient

I used 30 for K.

I then rearranged some pre-existing code to apply this formula to all the archived games I have, arranged in game number order. The complete results of this program are available below, as is an ELO ordered list of active Firetop Mountain users.

Update - Dec. 24 0315GMT

It has been suggested by Andrew White that the formula be changed to

K * (v -1/[1 + B ** ((EloOpp - EloOld) / S]))

where K ~ 25, B = 2, and S = 100

Ratings for new users would start at 1000.

This would make an average user have a rating of 1000. A difference of 100 points between users would indicate the higher rated user should be expected to win twice as many games.

Yaron Racah suggested a K of 40 and I have re-run the ratings. The order has changed a bit from the earlier run as users with fewer games are getting moved farther with the larger K value in use.

A running report as ELO ratings were generated
ELO ratings for active users

Update - Feb. 2 2001

ELO ratings are now calculated on the Main server and updated as each duel completes. The ELO ratings here wer used as initial values. For up-to-date ELO ratings see the gamerz.net page

I'm going to try to look at Glicko's, suggested by Yaron Racah and documented at http://www.glicko.com/glicko.doc.glicko.html. If I can figure it out I will post sample ratings here.