I can't tell you how many ranked games I've had ruined this season due to people troll picking or deciding they want to test new compositions in ranked instead of normals. I feel like the game needs some way of letting you block these people from getting matched with you again,
It's extremely unlikely (in low elo) you get placed with the same people multiple times, unless you requeue at the exact same time as they do. To avoid them, simply wait a minute before queueing again after the match.
There are basically two cases to consider; either you have an significant chance to get the same guy in your team, or you don't. If you don't, you don't need such a system, especially considering it could have negative effects on matchmaking (especially the needed time), even for people who are neither blocking nor being blocked. If you do, on the other hand, you could use it to screw around with the ranking system. Imagine a bunch of people in a low density MMR range decide to block the same person. That person would then neither be likely to appear on their team, nor on the enemies (since they also most likely have him blocked). Simultaneously that person would have to wait ages for a match. And thus, simply by blocking that person (and thus limiting their ability to both, practice and rank up) people could lower that person's rank.
It seems like a simple feature, but the impact on matchmaking is difficult to predict for us "common" people that don't know exactly how their algorithm works.
