How is league mmr calculated? @RIOT

"Do you have a 51% win rate? Enjoy having low MMR team mates then"

"Do you have a 49% win rate? Enjoy having high MMR team mates then"

From who you beat / lose to.

It gets really messy because normals aren't soloQ.

If I'm with friends I'm more likely to play my mains to guarantee we have a good game together. Their MMR gets buffed because we beat several teams with multiple golds + plats over a couple days. Their MMRs go up.

They queue up soloQ, suddenly they're the one bronze ADC in a gold game. They lose, their MMR goes down.

Who knows if it's more complex than that. The fact is, it doesn't need to be to end up as messy as it is.

That's a top CIA/FBA secret. And a bullshit if you ask me.

Wins and losses. It's that simple.

I seem to lose/gain about 30 MMR per win/lose. You can google the exact numbers for MMR ranges and divisions if you care that much.

has to do with your winrate, for example, I am gold 1 currently so I should get matched with people around 1700 elo, but I have a record of 40ish-20ish, so I get matched with and against people at 1800-1900 elo even though that is not my rank.

The higher your winrate the higher your mmr or true rank is, you will get matched with people ranks higher than you if you have a high winrate or true rank, and vice versa

You will also gain much more league points for having the good winrate, and lose much less also for having the good winrate, however, even if you keep this good win over loss ratio your gains and losses will become closer to even the higher you climb pretty much no matter what just cuz it is hard to keep wins up that much more than losses the more games you play

They wont tell you this. They lie about how matchmaking works when it was revealed by other company using same matchmaking how it works. They would never tell you how they calculate it.