Getting and Losing LP should be according to your grade.
Victory (example)
S = +23LP
A = +20LP
B = +17LP
C = +12LP
D = +6LP
Defeat (example)
S = -6LP
A = -12LP
B = -19LP
C = -25LP
D = -50LP
So 
would never be so bad due to big decrease in LP, and if they
continue getting D's rank them down per lost game.
This not only punishes those who just get shit on way too hard (seriously, have you never been hard-camped before?), but doesn't actually address trolls that much.
There are tons of ways that trolling happens that wouldn't result in a lower score. Have you had a support deliberately KS or steal farm? How about an AFK in game?
All this does is punish people who have a bad game and does jack shit against trolls.
You know how trolls are punished? By being banned, not by losing more LP.
"Welp I'm losing lane and getting denied farm which means my score is going to be shit anyways, guess I'll just afk since there's no point in trying anymore"
"Welp I'm support guess I'll take all these pretty CS so I can improve my score"
"Welp I'm jungle guess I'm never going to let the rest of my team touch my jungle or my buffs as it will hurt my score"
Brilliant idea.
You can always manage to get more than D, even if you are playing 1v2, and for hard camping thing, if u get killed 2-3 times by jungler in few mins than you are weak spot, play more def not feed and blame jungler as people usually do and results in trolling and dying on purpose.
I played with alot of players who say come mid and kill me, and that is not fair at all.
The LP increase in grading system should motivate players to performe better.
Dumb idea
nah fam
