Again, please riot change or revamp how the grading system works
I heard that it depends on the overall performance of how the players do with a certain chapmion but this doesn't make any sense at all, i've seen lucians do a hell of a lot better and not even get an S- , Plus our mastery grading of a champion shouldn't depend on how others do but should depend on our own performance so please set up a system were it encourages the player to play better, not just play for a score or compete with people smurfing.
**My suggestion: ** Make the mastery separated from getting an S grading ( because that's used for the hextech chest) so instead a simple quest to move on in mastery, there's this game called batteborn that to pretty much master the hero you have to beat challenges and they're things like killing 50 enemies while in mid air, or doing like 1million damage over all with the ult. In leagues case the masteries have a "class" so a simple quest with the classes could work. Example Assasins should be like get 150 kills with this champion to advance to the next stage. A Tank would be like recieve a certain amount of damage, Junglers would be like get like 50 dragons and 10 barons and a certain amount of gold. And stuff like this just simple quest i'm not saying it's something easier to do or that it can be done right away but! it would be nice to know at least that the team has it's foresight on improving this potential system. It's nice having a way to progress a champion but not when it feels random or half to do with the player.