Just an Observation that I Made

After every ranked game, whether I win or lose, I check the profiles of the Summoners who I was matched with. I noticed that the ones who perform the worst often:

• go on long losing streaks
• do not play the top 3 champions that they have the highest Champion Mastery points with
• get assigned a role that doesn't correspond with their most played champions
• For instance, Jim's most played champions are all Mages yet based on his ranked match history, he has been playing Marksmen.
• have few lengthy games that result in losses

There's many more things but those were just the main ones. If you decide to main Mid or any other role that is hard to get, you need to also perfect a secondary role...or DODGE every time you don't get your desired role.