http://en.wikipedia.org/wiki/Elo_rating_systemhttp://remi.coulom.free.fr/Bayesian-Elo/
http://en.wikipedia.org/wiki/TrueSkillNote: Trueskill is a modified version of the EloRatingSystem, it was developed by microsoft to be used for their XBox games. It will proably be simmilar to the EloRatingSystem. However I think certain factors in the EloRatingSystem is better for warlight. specifically the k factor. The k factor controls how much your rating can change based on how high your rating is (and time, but that's not relevant for wl), the higher your rating, the less it will change. I think that would be great for waright.