Don't allow a player to play a champ for the first time in ranked
It's awfully frustrating, im not talking to u all high elo that have a natural gift or whatever, but there are a lot of players in silver and bronze that tend to play a champ in ranked for the first or second time. that makes no sense! if u are required to get to level 30 to play ranked, for the same reason u should also have some experience with a certain champ before taking him to ranked.
it will also solve the "a new champ released let's try him out in ur promos"