Make owning at least 5 supports a requirement for ranked.
Because of the new auto fill function, which I think was a good idea mind you, people are getting support and then saying that they own no supports and then pick troll picks like Ezreal support. This ruins the game for some people, especially in higher elo but I suspect people aren't that stupid in higher elos than bronze, silver and gold. I honestly think this would be a good idea since a lot of players buy 20 carry champions and then jump into ranked to get auto filled support and then basically troll.