Never mind the Champion Mastery Points
How are the scores calculated?
I ask because I just played a game as Skarner in which I went 6/4/2 and got more gold than all but one other person on my team, but I got a C+ score. I've never gotten this low of a ranking without having bad scores across the board (i.e. negative kda, horrid cs, etc.). We did lose the game, but unless I'm mistaken, that's never had an effect on what ranking I get after a game.
I know some arbitrary ranking doesn't mean anything, but still, when getting an A or an S gets you 100+ more mastery points than you otherwise would, I'd like those extra points if I did indeed earn them.