Champion mastery isnt ballanced. Its almost all depens on if you win or lose.
Riot plz change the champion mastery to be more on the score and less on the win cuz i had 2 trollers while i was playing vayne and i got D becouse of them and you should also make champion ballance not in 1 game get s and d but to get only 1 grade down if you had the worst game.
will like if you will reply/listen to me , igratecatspro