MMR (Matchmaking Rating):

MMR, short for Matchmaking Rating, is an internal skill value used to place players in appropriately balanced Rocket League matches. It generally rises after wins and falls after losses, helping the game estimate a player’s relative skill level.

In Rocket League, MMR is used behind the scenes for matchmaking and ranked progression, even though players usually see ranks and divisions rather than the exact rating. It is also commonly referenced by the community when comparing skill levels or tracking rank changes.