[2021] I think MMR should be used as a standard to reach a rank rather than mostly used to matchmake but let me explain.

That is how our ranked system worked last season, there were very rare instances where your MMR and Rank were not 1:1. That's why you would see players have 1 or 2 bad games then suddenly get chain demoted, or chain promoted.

It's good in theory, because then your MMR is exactly your rank. The problem is that MMR fluctuates and isn't an exact representation of where you belong until you've played enough games. Our system uses your MMR as a center post, and then has a confidence check - that confidence gets more precise with the more games you play, because the system gets more confident in where you belong.

That being said, improving and playing outside of your MMR(either better or worse) will shift that confidence because the system doesn't think you belong at your old MMR before. Confidence is simply how far from your MMR you could possibly be playing for a given match. Sometimes you pop-off, sometimes you don't, but you are probably about this range as a player.

I explain this because while the system is building confidence, you as a player are getting shifted hard and it feels like you are just being thrown in between ranks. This is why the system before felt like it swung players hard and you would see posts like "This system is unfair, I had 3 bad games and deranked twice." - Unfortunately that's MMR, it will swing with your performance.

The new ranked system uses your MMR to converge your rank. The points you gain per match, your Ranked Rating, is modified by your hidden MMR. If your hidden MMR is higher then your actual rank, you will get more Ranked Rating points for a win and less for a loss(or vice versa if it's lower). The nice thing is that because we control the rate that it converges, we can give you a few games of a buffer in how hard having a bad game(or an insane one) really effects your rank. This is extremely healthy for ranked, in my opinion, because it means that your Rank and MMR converge, and it does so after a handful of games. So we get the same effect as the previous system, you just aren't wildly swinging between matches.

Honestly it's just a better experience, and is also easier for players to understand how many times they need to win or lose in order to go up/down in rank. If you just saw MMR, every time you played a match you would have no idea how much MMR you would gain for a win. In this system you have a pretty decent idea how much Ranked Rating you get from a win, because after one or two wins your Ranked Rating per win doesn't drastically change from match to match.

There are other benefits, I don't want to write a wall of text. But I think this will help in explaining why we changed from MMR as a rank. Thanks for the post, I find these topics super insightful into what people think about when engaging with ranked.