A few months ago I did a match as lulu support and my score was 7/1 and got a S+. Now I'm doing matches and getting 14/4, 10/5 even 3/0 and i am BARELY getting an A-. Has the system changed or become more strict? I'm playing my best and it seems like I could cough and get a S before now I have to cut off my limbs to do it
The exact way of calculating mastery grades isn't public knowledge. That being said,
It’s based on the champion and role that you just played in a game. So, for example, we look at Annie mid differently to Annie support. We take a series of performance metrics and compare how you do to all other players in your region in your champion / position combination. It is percentile driven - so earning a high score means you performed in the top x% of players on that champ in that position. The grade itself governs the point gains. (SOURCE)
Basically grades similarly to a bell curve, which in turn means that we have a server full of amazing Lulu supports.
I would suggest working on CS, objective assists, and possibly warding to bump up your grade that extra notch ♥
The mastery system is based on the average stats of that champion in that role. This means you can play things like support Nunu, intentionally feed like a madman, get carried and still get an S- with a KDA of 9/12/19. Just because Nunu is an awful champion and nobody plays him, let alone well.
Here's the game in question in case you were wondering http://imgur.com/dxQtuR6 I had the least damage dealt on our team, and at one point during laning I flashed into the enemy turret so I could snowball and ignite their Lucian(who was full health at the time) for no reason other than the fact that I could. That's not even counting all the times Kassadin killed me because I was dancing between their T2 and Inhib turrets.
EDIT: Found it in my match history too http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/2147817800/40115122?tab=overview
i went 20/0/14 as jhin mid and got a C+ but then went like 5/9/2 on urgot and got S+ [slayer-jinx-unamused] FiX YOUR SHIT RIOT
