So just finished one of the greatest solo que games ever. we dominated the other team and 3/5 people didn't die once. The other team surrendered and we get to the summary screen to see not one person on our team got an S rank. we averaged at least 2 As and 1 B (the other 2 didn't say). So can someone explain how this game just didn't get at least 3 S(+/-) ranks?
http://www.quickmeme.com/img/26/2644486c5411fc964ad5534d92cff801bfaff2254d53547c75368fc843be6be8.jpg
I think that's the scoring system.
That's the reason why, it's because you completely obliterated the enemy team and there was no challenge. That doesn't show your skill as a player it just shows how retarded the enemy team was. Everyone has bad days but the whole team having a bad day is unlikely and because of how short the game was.
A support would be harder to take any guesses as to why the grade was lower than you expected, but let's go by that Vel'Koz for a second...
He stomped his opponent, that's no doubt. However, the grading system goes by your own numbers vs. other people playing your champion. While he and Veigar were even in CS, and Vel was WAY ahead of him, 91 CS at 20 minutes is pretty bad. He did exceptional against his lane opponent, which is really what matters, but against the average Vel'Koz game, he was obviously lacking in the farm department.
The system is decent, but I feel as though it would be better if it went on a personal or game-by-game basis. That way, you could track progress against yourself rather than repeatedly being told that you're sub-par compared to the average player. The problem with that is the new Hextech system is already tied into the way grading is now.
Could you provide the match history link?
If you're support, it generally goes by kill involvement I think. 23 total kills and you were involved in 10 of them... Is under 50% involvement.
A) I know CS is a factor involved, and your whole team CSed like crap. None got even 50% of available lane CS.
B) I know there's some scoring penalty if your whole team is fed. If you're doing amazingly and your team is just ok, you'll get a better score than if your whole team is doing amazingly. In the former case, the system can see you're overcoming your team's mediocrity to carry, and the latter, you might just be riding the snowball of your team.
C) Remember that these are compared to averages. Bard in particular usually gets a TON of assists from roaming, and your 9 assists relative to averages is kinda mediocre. Your no deaths helps though.
All that said, from what I see, I'm surprised no one got an S-, but B especially can be a pretty big penalty.
This is coming from someone who has 26 S+ ranks on Rek'Sai alone, and 46 S Ranks on her.
I'm pretty sure it's based on other players of the champion. My friend could go a score like 3/0/0 on 
in a 40 minute game and still get a better score than me with something like 15/5 
. Only because Yi players tend to get way better scores than Azir players so the median is higher.
From what I recall, it compares you to everyone else who plays that champ and does well/significant. So is to say, you better hope Bard don't go 25-4 every game. But I don't think that's the whole story.
