not getting an s

Play a champion that you want to get an S on in the support role then farm minions whenever you can / when your adc is dead or not in lane.

Can confirm, I was the top in this game playing Mundo. Why did this happen to my friend

Put an image of the scoreboard please

OOF you're just one assist short of that S

CS and vision hold big parts, too, especially relative to the other players

Rengar commonly gets scores like that. To get an S, it takes your score and compares it to other players of that same champion. Its hard to get Ss on champions like akali, rengar, and veigar. Vision score and CS also matter a ton. If your vision score/cs was low, then you wont get an S. Also it was twisted treeline.

This was a 3v3. Vision doesn't enter into it. They probably did expect Rengar JG to have higher CS. Really, the calculations for grades on 3v3 haven't been revealed.

Didn't you incur Monster Hunter for not completing your JG Item? (In that case, you were graded low because you had a low income, despite your CS.)

(This is another gripe against Riot for removing 3v3. They didn't even bother to dignify it with PROFILE>STATS analysis representation. Maybe if they had treated it as a legitimate game mode, then things would have been different...)

Objective Control / Map Control is also graded, and as a Jungler, they probably expected your team to take one Vilemaw.

...

Yeah, looking over the stats, I'm pretty sure that your grade was juked from Monster Hunter on all of those lane minions.

and farm also counts and game length and so on ....who even knows now i hate A+ too

been trying to get a chest for so long now