Learn R Programming

Sabermetrics (version 1.0)

log5: Log5 Sabermetric formula

Description

Log 5 is a formula invented by Bill James to estimate the probability that team A will win a game, based on the true winning percentage of Team A and Team B. It's equivalent to the Bradley-Terry-Luce model used for paired comparisons, the Elo rating system used in chess and the Rasch model used in the analysis of categorical data.

Usage

log5(probA, probB, order)

Arguments

probA
Win probability of team A
probB
Win probability of team B
order
Determine winning probability of which team. 0 means win probability of A over B, and 1 vice-versa

Value

  • Returns (probA - (probA*probB)) / (probA + probB - (2 * probA * probB))

References

http://en.wikipedia.org/wiki/Log5