Suggestion for the grading system after game

So, am... today, i had that aram game where, you know it.. karma/morgana/jinx/zilean/jayce on enemy side, and we had yasuo main/suicide karthus/not-so-invisible teemo/scarycat ez/annie as me (you just know i was the best right ;))..

Ofc, in the beginning... we were losing so hard. As Annie, i was doing like 200-300 damage at most, before dying that is. No one followed a 3-player stun etc. Still... even though they could defeat us with all the lead they had, and jinx, and zilean... they didn't. Because we player properly and shut them well. Personally, i was able to set quite a few good stuns, take prio targets & cds, zhonya to avoid all kind of stuff etc. Also reminded my teammates about a few items (karthus with mr aura yet no banshee nor zhonya.. and teemo no gr wounds.. :d)..

Basically, even though playing from behind, we won. Hard. After game, i got honors for not giving up & teamplay. (10/13/16, 19 - ik, but i focused on keeping the stun up so enemy team cant come say "hi")

I got C-.