@Riot: Suggestion to implement Champion Mastery into Ranked use.
"First time X," types are a huge problem for people in ranked games who'd actually like to win games. Since Mastery currently doesn't actually do anything, I suggest making reaching a certain level of mastery (possibly 2 or 3, that's not unreasonable and requires you to play a decent number of games) with a champion a requirement before they are eligible for use in Ranked games.