ARAM Champion Mastery??
I just played an ARAM game with a Sona.
She had a final kill score of 3/1/38, and participated in 41 out of the 42 kills we had. Her one death was an execution so she could go buy items. She was the 2nd highest in gold, and healed almost as much as the Soraka on the other team. She had 24 CS, which was perfectly fine because the CS was really going to our carries. She also helped with all structures that we took down.
After the other team surrendered, in the post-game lobby, I ask her what her champion rating was for the game.
A "B".
What are we missing here? I thought you get a higher rating from playing good, and yet here I am with a higher rating with an Amumu. If a 41 KDA and a 97.6% kill participation, along with a 100% tower destruction and 13.6k healing, isn't enough to net even an A, then what is?