Calculates the K factor for the Elo rating system based on player rating, number of games played, and optionally a binary elite player identifier.
kfide(rating, games, elite = NULL, kv = c(10,15,30))A numeric vector of player ratings.
A numeric vector with the number of games played by each player.
If not NULL, then a binary identifier for
elite players.
The three different K factors that the function can produce.
A numeric vector of K factors.
This function is designed to be used for the kfac argument
of either fide or elo. It returns
kv[1] for elite players, kv[2] for non-elite
players with 30 games or more, and kv[3] for non-elite
players with less than 30 games. The default is the current FIDE
implementation which uses the K factors 10, 15 and 30. The K factor
of 30 was changed from 25 in the year 2011. In this context, elite
players are defined by FIDE as being those who have reached
the rating 2400 or more at any time in the past.