Fix your post-game ranking system, Riot

Dear Riot,

Please fix your grading system. How is it that when i go 26/2/17 as i get only an a+, even though i went only 14/2 as a few games before and got an S? I even got more than double the stats of damage dealt compared to the person second to me. Does the algorithm look for specific attributes in a game that i did not achieve? I have had this dilemma happen to me before, but this was really the straw that broke the camel's back for me.

Thanks,

Max "Veigar"