Having an unstatistically low winrate??

Okay, so I'm in Silver V, no big deal. But somehow I'm literally getting hard swept every game. Out of the last 20 games, I have won 5. If this were a 4 or 5 game losing streak, I could blame this on tilt, maybe I'm just doing something wrong, w/e. But no.

Even if you're intentionally feeding for 20 games straight (which I have done on accounts), statistically, your team will be able to carry you around 40% of the time. Your team, will just get so strong, that it doesn't matter if you troll.

Now, when I say I'm getting hard swept every game. I'm literally saying that 10 out of the last 15 losses, have been 20 minute stomps where every lane goes 0-5 and every player runs it down mid and tilts. I have no clue what astronomical feat of chance it has to be for this to occur, but I have literally never seen anything as poor in my life.

Quite personally, I refuse to believe that my MMR is so high, that I'm apparently sandbagging 4 other people in every game so we get matched up with golds and plats.

What's going on?

PS. This account is not the one I'm talking about. OP.gging this one won't tell you much except that I really like to play Shaco.