For the longest time now there has been a very consistent kind of boards post; the kind where people state the very real issue of having people play whichever new champion that just got released first time in ranked. A lot of people have been asking for a fix such as having the new champion unplayable in ranked for the first week or two, but I propose something more secure.
Though to be honest, I doubt it's a new idea, but it's pretty much failproof. Instead of making the new released champion unplayable in ranked for the first week or two, how about we just make it so no one is allowed to play any champion without having at least MR2 or MR3 with them? That way not only are people unable to play new champions first time in ranked, they're not allowed to play any champion first time in ranked. According to my roommate who bingeplays Mobile Legends, they have a system where you're either not allowed to play champions in PvP or Ranked if you don't have enough "experience" with them, basically the same thing as our currently implemented Champion Mastery Rank system.
I'm not sure why Riot hasn't done this already, it seems pretty obvious, easy and failproof to me. Though this solution, being this obvious, I doubt it's really a new idea so I apologize if anyone else already has suggested this.