If you've been keeping up with how Riot does things in dynamic queue, then you know that premades are pushed into games with solos that are a higher MMR than they are in order to "balance things out". Which means as a solo player, every time you're in a game with premades (the vast majority of your games), then the average MMR of the match is actually going to be lower than what it should be for you cause of the premades (probly one on each team) being from lower MMR.
Now if you know how LP losses and gains work, you realize the incoming problem with this. You lose more LP per loss and gain less per win when the match's average MMR is below your rank. And you gain more LP per win and lose less per loss when it's above your rank.
Well, since the MMR of the match is going to be less than what it should be for solo players, we're naturally going to lose more LP per loss and gain less per win. At first I didn't understand why I was struggling so much. Then I started looking at lolnexus and remembered the premade thing. I know Riot has been rewarding people left and right for playing as premades, but to go as far as to actually punish solo players? This is just a giant kick in the balls.