Ranked Criteria Changes

I've noticed in many ranked matches, specifically in low elos, that there are summoners who decide to play new champions in a ranked match. Personally I feel like this is unfair being that there's already so much risk going into a ranked match and adding more of a risk by having a player who doesn't know how to play that champion ruins the competitiveness of ranked and honestly keeps a lot of people stuck on low elo. tl;dr people who play new champs in ranked suck

Changes: I feel like there should be a criteria set in ranked, not only for level, but for how many times a player has played a champion among other factors so that less people come into ranked matches choosing to play new champs and screwing it up for other players