Mastery Scores should give suggestions for improvement
I'm not 100% on how the formula works, but if it is mostly based on your score and performance, then I think the end game screen should also give you suggestions about how to score higher. If you didn't cs well and it gave you a worse grade because of that, it should tell you. If you died more compared to others who played the same champ, it should tell you. Think this would be a good way to help players better themselves.
