How about a "test" to get into ranked.
I don't mean a written test or winning so many games, but how about something that you are going to do anyway....play normal draft games...like a certain number (50?) to be able to join a ranked game. You will probably be working on this anyway as you make your way to owning 20 champs,...BUT..
here's the stipulation: Your avg deaths need to be under say 5 or 6. THAT is the problem in most bad games. People take death too lightly. I just got out of a 26m game where 3 of my teammates had double digit deaths. If people were forced to treat death more seriously, maybe we wouldn't have so many losses because of bad dives, chases, 1v1s just to 1v1, etc.....and actual balanced games where skill and strategy matter. Right now, it's who makes the least stupid plays, wins.