All the ratings are calculated based on statistics during last three months. Thus, we get a dynamic rating system where newcomers and old players have equal chances to be in the top.
Rating system consists of four scales:
House Statistics - reflects victory persentage for a particular House (2nd-6th places count, victory gives 100%, second place 80% etc).
Westeros Statistics - Mean value of all ratings and players that took part in calculation. Only victories count in global house statistics.
Leader board - is a list of players that have at least 48 hours of game experience and at least 10 finished games. Players who did not visit the game withing 7 days are not displayed.
Passing rating - playes, when they create a game, may set passing raiting in it (not more than their own rating). Player with a rating lower than the passing rating will not be able to play unless he or she substitutes a leaver.
I am planning to develop a number of achievements that will be displayed in players' profiles. With your support, of course :)