Saying this for 2 years: Autofill in diamond decides games.
I literally went through 5 champ selects, just to get matched with an autofilled top lane who even after 2 ganks which he got a kill and an assist, and I burned the enemy top laner flash. He then dies 3 times in a row 1v1. Alright. And then he says "im autofilled". OK. If you get autofilled jungler, adc, mid, doesn't matter, and they're going against a main of that lane, you're now playing a 4v5 game.
Last year I peaked at d2 and then after that, every game was decided by 10 mins with "sry, I'm autofilled". I got so tilted I dropped to d5 and stopped playing ranked. Same thing is happening now, d3 right now and I just see whenever I lose a game, that dude was autofilled and had no idea what he was doing. Granted, not everything is rito fault, dumbasses get autofilled and then pick jayce or lb and feed. Like why wouldnt you just pick some braindead tank or some point and click mage ? But ok, let's lose games in champ select, it is so much fun man.