# Elo Rating Formula

Last modified by Samuel White on 2011/08/25 22:32

The Elo Rating Formula for predicting winning chances of two players in a match is a commonly used formula for rating systems. It is defined as follows. Assume player A with rating *R _{A}* and player B with rating

*R*are in a match. The expected probability

_{B}*E*that player A will win the match is:

_{A}