Testing a Champ IN RANKED!!!

Hello anyone that is reading this and I hope this will get noticed! I apologize in advance if the formatting seems dull, but this is the first time I'm trying to make a change in our beloved League of Legends.

At the time I'm writing this, it's 3 days until the end of Season 6. Since I'm in low ELO (Silver I), I wanted to give my best to push and get to Gold and get that shiny (for me) new banner. So I've played a lot of games in the last couple of days and it was going fairly good, until... I'm at 80, or so, LP in Silver 1, all I need is one win to get to promos for Gold. You all know the feeling, the excitement, almost there! We start the game and it ends after 20 mins. We lose. Why? Because a player chose to test a champ he just unlocked in Ranked. You can imagine how I felt. I chilled and thought it won't repeat today anymore. Like hell it didn't! I get to my promos, I win my first game and BAM, in the second one AGAIN someone is playing a Champ for the first time ever and that is in Ranked. Now I'm blabbering so much, so anyone who reads this, can understand my frustration.

Now to the point. Dear Riot team, I have a suggestion how to improve Ranked experience and avoid situations like I just described above. After the Champions are banned and the picking starts, there should be a piece of code, a script, that can "calculate" or determine how many times a player have played a certain Champ. In case a given Summoner never played a champ that he posses, or he played less than 20-30 games with it, he should not be able to pick him (like a banned champ, for instance). Or other idea is that the Champion is not listed at all, so it doesn't even cross his/hers mind to try a Champ in Ranked.

I think this is a decent idea and would improve the game in more than just one way. One less reason to get frustrated over someone who is just ruining others games for fun and because he can.

Any suggestion on this topic and other ideas are more than welcome! Thank you for reading and I hope for a change soon.