I just went 25/7/13 on Brand.....only an A+
Like seriously, whos D* do you have to suck to get an S rank around here?
Like seriously, whos D* do you have to suck to get an S rank around here?

It doesn't just matter about the KDA it's also about how much objectives you get , ward placement , and your CS. KDA does matter but so do a lot of other factors. I hope this helped , sorry for your loss though dude [sg-soraka]
Show me a screen shot of your match and i will tell you why you didnt get ur S or S+ (:
If the rest of your team also did incredibly well it may balance up, so let's say if you did 25/7/13 and an ally did something like 20/1/10 then you didn't do league's better relative to the rest of your team and it could've just been a massively one sided game.
im going to go out on a limb and say you played it support not allowing you to hit the thresh hold of cs needed for a s or s+ for a mid lane champion as he is not classified as a support you will need x amount of cs to retain a s or greater score.
CS plays a big part. Or in a support's case, wards. If both of those are pretty low by the end of the game, you won't get an S.
KDA is only part of it. 7 deaths also takes away from part of that.
CS, Warding (placing and destroying) and objectives are also taken into account.
Plus, the % of kills vs the total in your match is a big part (as I see that match had a total of 58 kills and you were 66% of it, you wanna push it higher if you want it off of kills)
Lol, u’ll have to suck the players that consistently play well on Brand. He’s a relatively easy champion, and with each S the average required to be in the top percentile is raised. The best bet to improve ur chances reliably is to improve ur CS and improve ur warding.