Mastery Grades Make Absolutely No Sense.
I don't know what algorithm you guys are using to calculate the mastery grades post game, but it makes no sense. For example last game: I got 8/1/5 as Jinx, I get a B-. My Support goes 2/1/17 as Morgana, gets an A-. Yi goes 8/4/0, gets S. Yi bias confirmed.