SoloQ
SoloQ being based entirely on wins and losses is what is hurting this game. I know Rito wants to reward the players who have good teamwork, and not just individual skill, but the problem is that it doesn't matter how much teamwork you have, it matters how much teamwork your team and the enemies team has. When your team wins all the early team fights, even 4v5s, but your adc split pushes all game and feeds the enemy so much that you lose the last team fight horribly, the first part of the game doesn't matter.
Last game, I started off 0/2/8 on support Nautilus. I ended 1/5/8 because their Caitlyn was 17/0/4 because she was picking up free kills on a Vayne who thought she could dual her all game. Their team had 30 kills. Vayne was 12 of those. This is why SoloQ rankings are not accurate. Each game is determined by who has the troll, who has the feeder, or who has the afk. SoloQ does not care how good you are as a "solo" person. It matters how good your team is compared to the enemy team