Small change to ranked to reduce the amount of casuals in ranked que

We all know its a problem. So many people that havent learned the game yet jump into ranked and get you demoted, screw your promo's, and generally play poorly.

Here is the plan. A pre rank qualification process. Not if you play bad you end up in bronze, thats not good enough. You should have to play 5 games, and based on your performance, not necessarily just wins. KDA, tower damage/destroyed, wards placed, and everything that people who are playing ranked should be doing. based on that you should have to get a minimum score to even get into the ranked que to go through your placements. I think this would keep the people who just arent ready yet out of the ranked system until they are at least ready to compete in bronze...which would redifine the skill level of people that are in bronze, because they would know to ward and at least not go 0-15-2 every game they have ever played with their favorite underpowered and unvialbe champion in the wrongest of roles possible

suggestions thought comments feel free.