Can somebody explain why there are some teams with 6 matches played while we only have 4 matches played in premier when there have only been 2 match weeks and according to riot you are only allowed to play twice per week?

First of all, sorry about my bad english. I'm sentinel or controler (KJ & Brimstone) currently is Diamond 3, and I think I don't deserve my rank (not boosted). My aim skills aren't that good compared to other player in this rank disparity,...