Another thing to point out is that the formula currently is not penalizing for Betrayals (I know Bungie stated they're supposed to). They aren't taken into account in the ratings currently, although I'm assuming this is another thing that will update for Season 2. In addition to the betrayal penalty, I think that the player who is betrayed should not have that death counted in their rating as it currently is. That way, betrayals only hurt the player that commits them, and no one else is victim (besides the fact that you're team might lose).