You won so hard the enemy surrendered? Nope sorry no S for you.
The system should take into account the time of the game. If you go 9/0/1 that doesnt sound that great unless you consider that it was a twenty min game. Does anyone else notice this? I was playing sona support. So like you can get an S at 20 min but Its hard because I cant just get a bunch of kills. Late game is where I stack assists in teamfights, but 20 min is barely out of laning phase.