I had a game recently where I was absolute garbage on Ryze (3/13/9, 4.5 cs/min, 29% kill participation) and I still got a C+. Made me wonder if it was even possible to get a D or F. So what's been your biggest fail this season and how bad of a champion ranking did you get?
F doesn't exist. It's S+ to D-. The range is displayed in the post game screen.
Grades S through D are displayed here: http://na.leagueoflegends.com/en/page/features/champion-mastery
It almost sounds like it is time to feed for science.
I've gotten a D. Not a proud day.
I have gotten a D before. D+. I did very poorly in urf
Pretty sure lowest I've ever gotten was C-, and those are like 0/3/0 stomps that typically feature at least one afk.
I guess F is for intent feeding levels of bad.
I went like 2/14/5 my first time 
and got a D.
Yeah.. Unfortunately I've had quite a few of those when I first started Normals. I'm proud to say I got my first S+ a few days ago with Corki though :)!
Got a D before, that game I lagged so hard and can't even csing, went something like 1/17/5. I don't even if F is possible.
I honestly thought that the rankings went from C- to S+.
I didn't even know D and F were possible rankings...
I believe you get an F if you DC / AFK all game but come back near the end
When you hover over the circle after a match, it shows letters of S A B C D, and there isn't even an F on the list. So I would figure you can't get one, but it's quite possible that you could get a D- but I've never seen one. Maybe if you just afk or something like that.
i went 0/10 as cait
and it wasn't a D..i don't understand how tbh
https://puu.sh/uiVYk/8b92c81179.jpg
I have a D- somewhere but both of them were URF games.
I have gotten many. Yes, I suck.
I got a D- for using Garen in Aram. Can't do anything, Ended up with something like 0/8/0. I also did basically no damage to minions, champions, or towers; just walk in and die.
[slayer-jinx-catface]
I don't think I've ever gone below a C+
I don't know if F exists, but for D yes.
Believe it or not, the worst i've got so far was a C- so might be possible
