What is the ranked MMR?

What does MMR stand for? Well MMR, or Matchmaking Rank, is a hidden score that determines which rank you are in whilst also acting as a way to place you against opponents with roughly similar skill levels to yourself.

How much MMR do I have?

You can determine if your MMR low, high or usual for your current league by looking at your LP gain/lose. If your LP gain is equal to 17-22 then you MMR is normal for your league and you will play against players whose league is close to yours.