Its basically matchmaking based on talent, and we see it in a lot of popular games like Fortnite.
Your rating will eventually accurately represent your ability. Check enemy overview and seasonal MMR, win rate, abandon rate, headshot rate, and other useful. How to check your Rocket League Match Making Rating (MMR). Keep playing, perhaps solo queue in order to get a more fair representation of ratings on the teams. The only place it is possible to not gain many points per win is at the top, where players can only get a few points per win due to rating difference (such as when the pros play) and similarly it is possible to lose points at the bottom for the same reason (that the rating difference is so large that you cannot get away from it). In the case you outline, yours either declined more because you had not reached 20 games, or because your rating was higher than your teammates. The rank and division that you see is a visual representation of this. It's a hidden number that corresponds to one of 23 ranks that you can be placed within. Playing with a player of a different rating will effect the way that the shared rating points are awarded or removed. MMR, or Match Making Rating, is a hidden number value that represents your rank in-game. MMR stands for Matchmaking Rank, and is a score that determines who you face off against in Rocket League. The rating system in Rocket League is a custom implementation of the Elo rating system. The animation will often 'hold' until the next game if the game doesn't. It's more likely you lost the previous match and went down a division but left before the scoreboard screen. That is the way that the base ranking system works that is used to calculate rating in Rocket League. You left before the rank screen popped up on a loss most likely before the winning game and mmr caught up to you. Once you finish 20 games, then it will become normalized. Hey there MMR is lost or gained by losing or winning a match, so if one of your teammates leaves a match before it ends, the fact that he left will not.
Once you finish 10 and are ranked, it is still susceptible to more movement than normal. During the first set of games your rank is considered to be provisional, and is more susceptible to swings.