Is ARAM Rigged?
So.. I'm pretty confident that Riot tries to decide who wins matches before they even begin.
On my current account I have logged 848 games. I have exactly 424 wins and 424 losses. I don't think that's a coincidence. I've also noticed many other players with very high game counts have almost 50/50 ratios.
Furthermore, I swear in some games, teams either do more or less dmg despite their build/champs. I think they're trying to set handicaps or something to make it more "fair" for everyone who's playing.