Getting an S with Azir.

Okay so first of all, Not sure which board to put this on so I'm putting it on gameplay. I just played a ranked game as Azir, one of the most difficult champions in the game, I got the rating of A and here is my KDA and accolades along side the team comps. Blue team; Top-6/5/7 Jungle-1/9/8 Middle-7/6/6 ADC-1/5/8 Support-1/6/7 Red team; Top-5/3/18 Jungle- 5/1/6 Middle- 12/5/12 ADC-9/3/7 Support-0/4/18 Highest kills; 1) 12 2)- 9 3)- 7 4)- 6 Damage Dealt to Champions; 1)- 38k 2)- 37k 3)- 23k 4)- 19k Largest Killing Spree; 1)- 7 2)- 5 Largest Multi Kill 1)- Double Kill 2)-Everyone else but Thresh 1 3)- 0 Turrets taken; 1)- 3 turrets Gold earned; 1)- 15.2k 2)- 15.0k 3)- 14.6k 4)- 14.4k -Ontop of that my gameplay was excellent -I avoided as many deaths as possible -I landed 4 Azir ultimate insecs -I saved allies -helped other lanes snowball -Helped with dragons -Made shotcalls to take second tier turret while allies thought we should back, we get turret and back safely without loss (Twice) -Made Baron call And due to Match history Advanced details being down currently I can't tell how many trinkets I placed, but I knew I was placing them all the time because it's a habit of mine, I rarely have more then one charge of trinket. Is there anywhere that specifies how to get S's or how the grading system takes you into account?