An Implementation of Mark Glickman's Glicko-2 Algorithm for R. It closely follows Mark Glickman's suggested implementation which can be found here.
devtools::install_github("schw4rz/glicko2")Update ratings for all players with strengths and matches stored in data.table objects created using the InitializeMatches and InitializeStrengths functions (example from Mark Glickman's suggested implementation paper).
library(glicko2)
# generate data
matches <- InitializeMatches(player = c("A", "A", "A"),
opponent = c("B", "C", "D"),
is_winner = c(1, 0, 0),
period = 1)
strengths <- InitializeStrengths(player = c("A", "B", "C", "D"),
period = 0,
r = c(1500, 1400, 1550, 1700),
RD = c(200, 30, 100, 300),
sigma = 0.06)
# calculate updates for all players
UpdateGlicko2Periods(strengths, matches)Result is a data.table object with the history of Glicko-2 ratings for each player and period:
player period r RD sigma
1: A 0 1500.000000 200.00000000 0.06000000000
2: B 0 1400.000000 30.00000000 0.06000000000
3: C 0 1550.000000 100.00000000 0.06000000000
4: D 0 1700.000000 300.00000000 0.06000000000
5: A 1 1464.050671 151.51652412 0.05999598429
6: B 1 1398.143558 31.67021528 0.05999912373
7: C 1 1570.394740 97.70916852 0.05999941947
8: D 1 1784.421790 251.56556453 0.05999901176
work in progress