Glicko 2 Ranking code.

This repository contains code for ranking according to Mark E. Glickmans "Glicko2" ranking system. See

http://glicko.net/glicko.html

Using the code

There are are couple of exports, which are the main interface to the code base. Suppose we have

Rating = 1500,
RatingDeviation = 200,
Sigma = 0.06
Opponents = [{1400, 30,  1},
             {1550, 100, 0},
             {1700, 300, 0}].

Where each opponent is given as a triple {R, RD, S} of respectively the rating of the opponent, the rating deviation and the score. A score of 1 means we won and a score of 0 means we lost. A score of 0.5 is a draw, but I am not using that in the code.

Calling

glicko2:rate(Rating, RatingDeviation, Sigma, Opponents).

Returns a triple {R1, RD1, Sigma1} of the players new rating, rating deviation and sigma/volatility value.

Alternatively, you can generate a configuration configuration(350, 0.06, 0.5) which defines, respectively, the initial rating deviation, the standard volatility base and the value of tau in Glicko2. The tau value says something about how much volatility means as a factor. I suggest tuning these for optimal values.

To use your configuration, call:

Conf = glicko2:configuration(360, 0.06, 0.5),
glicko2:rate(R, RD, Sigma, Opponents, Conf).

Another export is phi_star/2 which is an internal step in the Glicko2 scheme. This step is useful for tuning, hence it is exported.

License

MIT