No. Decaying in League of Legends has no impact on your MMR. If you decay from your current rank to a lower one your MMR will stay higher than your actual rank. For example, if a Diamond 1 player decays to Platinum 1, he will continue playing with D1 teammates.

Does MMR in normals affect ranked?

Does ranked MMR affect normal games, TFT, or flex MMR? The answer is no, each game mode has its separate MMR calculator and is not interlinked with each other.

Does MMR determine rank?

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.

Do you lose MMR in normal games?

The only way to lose MMR is by losing a game. Playing with someone who is ranked lower than you will only affect your MMR gains and losses.

How much MMR do you lose per loss?

Each ranked match of Dota 2 increases or decreases your MMR. Winning a solo ranked match gives you +30 MMR while losing one takes away 30. Similarly, winning a party ranked match gives your +20 while losing takes 20 away.