So what's the real deal with MMR?

Dezyre·4/17/2018, 11:21:18 AM·4 votes·3,300 views

Going straight to the point, I feel like winning streaks have less impact on your MMR than losing streaks do, or at least that's it for my account. I've been playing quite a few ranked games (SOLO queue only, I never duo) this season and even at my winrate peak (56.2% winrate on 350+ ranked games) I would lose 18-20 LP and win 17-19. I didn't really care about this until I came across several league streamers winning more LP than they'd lose with a 50% winrate and a LOT of games played (meaning that their MMR should be accurate). So, Riot, what's going on here? Is there a real algorithm that calculates MMR or do each of us get a Rioter who decides how many LP we win/lose based on how they feel that day?

5 Comments

Chermorg4/17/2018, 1:01:47 PM1 votes

LP gain/loss is always based on what the matchmaking system thinks is your chance of winning the game, and more significantly on your MMR in comparison to the MMR of your rank (division/tier and LP within that). Matchmaking tries to get every game to be equally matched within 1% chance of winning - i.e. each side has a 50+/-1% chance of winning (so the most disparity would be 51% chance one side and 49% chance the other side). If your team is on the 51% side, and you lose, that may cause a very small shift in your LP from the baseline gain/loss - 1 LP or so.

Now, the baseline is calculated from your MMR in comparison to where you are standing in the ladder. If your MMR is at a Gold 2 level, but you're ranked Gold 1, the system will "take" more LP from you when you lose, and give you less when you win - because the system is trying to move you to the rank that fits your MMR. In your case, it sounds like you may be on the ladder slightly higher than the system thinks you should be - and so the system is trying to find the balance between you and those around you.

That being said, 18-20 and 17-19 are within 1 LP of each other - this could also be very well due to random matchmaking and/or team skill - especially in Diamond/Master.

T4underbolt4/17/2018, 8:42:27 PM1 votes

This system is rigged. I matched with a friend who has same MMR as me but different division and while I was getting total trashes and toxic players while playing solo I was getting decent players when in duo. Same MMR as riot claims and yet so much difference. Open your eyes. Riot just lies about how matchmaking really works.