I've noticed that ranked is a bit of a joke in the lower elo. I was previously 1400, but then dipped dramatically all the way down to 1150 when I was getting paired with teams that didn't do something right. It only takes one person to lose the game, and of those games when I lost elo to 1150, I can only say I honestly had a poor performance in two of them. Having a person like that in every game though is just stupid, and I don't know how it happens.
That being said, I just played a game as Vayne and had to carry my team with a score of 21/4/13. The kills difference between the two teams was 47 to 41, which just goes to show what I mean. I'm currently at 1250.
Lastly, I recently started a team of 5 to compete in Go4LoL, with myself being the jungler and Oracle supporting. I'm the only one under 1400 - 1600 elo on the team
, but yeah. Wish us luck.