Adding a "X" game buffer to newly unlocked champions in ranked

It would be a fair assumption to state that people play ranked with the ultimate goal of achieving victory, more so than other game modes where nothing is on the line beside our pride and dignity. One of the MANY roadblocks to that is having someone attempt fate and pick a champion with high difficulty like for the first time and proceed to "int" their faces off. I am not saying picking someone for the first time is a reportable offence, but doing so in ranked when everyone is giving 100% is dodgy if not terrible. Furthermore, this has proven to add additional stress to your teammates and will increase the chances of tilting.

Solution?

Add a buffer where the champion has to be played "X" number of times in order to be available for ranked. 10 feels like a nice number but definitely add suggestions. This promotes players to actually learn what the champion does and know roughly where the strengths and weaknesses lie in a less hostile environment and will add to the overall player satisfaction.