What's the New Deal with MMR?

[Kaawumba-1133]

Scott wrote a long and informative post on Groups and Matchmaking in Overwatch. However, rather glaring in it’s absence was any mention of MMR.

So is MMR gone? Are matches now made entirely by SR? That’s certainly what this post says.

@ScottMercer

Group size doesn’t matter for the purposes of calculating expected win chance for a game, what matters is the SR of the players on each team.

@ScottMercer

What was the quality of the enemy team and your predicted win chance? You gain more on a win if your predicted win chance was <50%. You gain less on a win if your predicted win chance was >50%.

@ScottMercer

Whenever it wants to make a game, it calculates an expected win percentage for each team based on the SR of all the players. If one of the teams doesn’t have at least a predicted 40% win rate, then we simply don’t create the game.

But the post doesn’t say that things actually changed, so…?

If MMR is indeed gone, how is matchmaking handled for decayed players? Are decayed GM’s being matched against diamonds now? Or does “MMR” still exist, but only for decayed players?

Scott does say that the SR buff on returning from decay is still in place.

@ScottMercer

Did your 3000+ SR recently decay due to inactivity? If this happened, you’ll gain more SR on a win until you get back to your “undecayed” SR.

An aside: This post definitely changed things, without asserting that it was a change. Here, it is asserted that group size has no effect in determining win probability and hence matchmaking.

@ScottMercer

Group size doesn’t matter for the purposes of calculating expected win chance for a game, what matters is the SR of the players on each team. Since grouping status doesn’t change the expected win chance, it doesn’t affect the amount of SR change you experience after a win or loss.

This did not use to be the case:

The other issue is how do we model the synergistic effects of players being together in a group. As you noted, they have access to voice chat. Now here’s where things get interesting. This “massive” advantage actually differs based upon the skill rating of the group members. Based upon the data we’ve seen groups of low to mid SR players don’t see that much improvement to their win %. Higher SR players do see more notable improvements, but it’s not as huge as you might think. Still, we do take this into account when we predict the win% for each team. Regardless of how the data looks, we do know there’s a perception of a large advantage for groups. That’s one of the reasons why we explicitly try to match similar sized groups together.

from Overwatch Forums

There was no admission of when this change happened. However, it was detected by Your Overwatch (Overwatch: Has Blizzard SECRETLY Fixed Ranked!? - YouTube) a month ago.

[DrAlucard-11130]

February was when they redid the matchmaker, they mentioned the gathering of data in the matchmaker forum post. It’s way better than it was in November and January that’s for sure.

[Kaawumba-1133]

February was when they redid the matchmaker, they mentioned the gathering of data in the matchmaker forum post. It’s way better than it was in November and January that’s for sure.

That’s a decent guess anyways. It certainly wouldn’t make sense to change the rules in the middle of data collection.

[KinetaTwix-1813]

You can ask him on that exact post, I remember him answering people for a while.

[Kaawumba-1133]

I did post in that thread, but it wasn’t till post 200 or so (because I didn’t see it right away). I don’t know if he reads that far in his topics. Most of the posts are pretty in the weeds at that point. Hence, the new topic.