NextdoorMMR

Joking aside, I felt I could clarify this a bit. We aren't actually changing the rank that Challengers can match, we are changing the skill or MMR gap between two teams, which much more directly impacts the chance of the stack winning. It's similar, but the distinction is important because by using MMR instead of rank, it is not affected by us widening Diamond and Master.

Basically, instead of a 5-stack Challenger team getting opponents they beat 95% of the time, they will now only get team a balance that a good solo queue player would also get, meaning they will either:

• Lose just as often as solo queue players and therefore not climb faster, so it's not an advantage anymore (no more win% advantage)
• Not find matches at all because there are very few 5-stacks that would have their MMR close enough to the Challenger stack for the match to be fair. So instead of queuing as a 5-stack, they will queue solo to find...

Actually, if you have a high MMR for your Rank (e.g., you're in Gold but have a high MMR and are getting hard matches), the game will give you more Ranked Fortitude and therefore shields, and it will also give you more Rank Skips, so you can still move up even though your matches are in the 50/50 range.

The same thing goes for Diamond. If you are in Diamond IV but have the MMR of a Master, yes, you may only win 50% of your matches, but you will get +15 for a win and only lose -10 on loss.

So you would go, e.g., +15 +15 -10 +15 -10 -10 over 6 matches (3 W 3L, 50%), but be up +15 VP after. Basically, you would net +2.5 VP per game while going 50/50.

The way we measure the MMR system's effectiveness is by asking it for every game, who it thinks will win, and then seeing how often it guessed right --- basically its accuracy at knowing who is good at helping their team win. We do this across all games every day and track how well it's working.

The current system is currently significantly more (15%) accurate at predicting whether you will win matches than it was before, so therefore the MMR you have is more accurate at judging players' abilities to win matches.

The MMR system also places a fairness prediction on each match, meaning the chance the better team will win (e.g. 50%, 55%, etc.) So we also measure how precise that prediction is. We do this by looking at all of the cases where the system guessed, e.g., "55%" and see how often the better team really wins. It's currently right at 55%, whenever it says 55%. It's also at 59% whenever it says 59%, etc. So we have pretty good confidence in the system's ability ...

• No, the MMR system is currently robust to 5 stacking. The MMR system takes into account the difficulty of a match. If 5 stacks have easier matches, the MMR doesn't move much if any and doesn't inflate. MMR currently has very little inflation at all, if any.
• 5-player parties currently use a different matchmaker in ranked, so they can only play against other 5-player parties. They never play against randoms, trios, or duos.
• Because of the two above points, 5-player party MMRs do not affect the MMR distribution. If they have high win rates, it's more a function of them doing well against other 5-player parties, not against smaller groups.
• You're welcome!

No, MMR doesn't follow a 10/15 pattern. It is relatively stable and only moves significantly when there are unexpected outcomes. It usually goes up and down about the same each match.

We are definitely talking about ways to consider match fairness and contribution in the VP gain outcome. The goal would be to make the update at the end of the match feel more fair, while at the same time making sure the ranks were still accurate.

I can tell you that, looking at your own match history over the last 120 ranked games, the balance of rank and MMR between you and your opponents has been really even, so you've had a pretty fair schedule as it were.

If you are getting -15/+10 then that does mean your Rank is above your MMR right now. Looking at your history, your MMR is on a bit of low swing (which is normal, everyone's oscillates up and down a bit), but it tends to sit around the Diamond IV area on average.

The range of possibilities for all Diamond is everything from -15 to +15.

The way to tell where your rank is relative to your MMR anywhere Diamond+ is:

• If gains and losses are similar, your Rank is at or very near your MMR.
• If you gain more than you lose, your Rank is below your MMR.
• If you lose more than you gain, your Rank is above your MMR

So if your MMR is in the D4 range, and you are also D4, then you would see your gains be similar to your losses. Around +/- 12 or 13.

Keep in mind it's not just your tier, but your exact VP. So your MMR could map to Diamond II 50. So when you are below 50 you will net positive, and when you pass 50 it will swap the other way. Like, +13/-12, then to +12/-13. So change can happen within a rank.

To your first point, that is not what we see in the data. That happens sometimes, but it is by far not the rule. If two teams have the same MMR, it doesn't matter what their ranks are consistently in millions of millions of data points. So what you are seeing is likely confirmation bias.

To your second point, we are going to have to disagree. Data shows clearly that heavily unfair matches definitely lead to players leaving the game, and this is very consistent across millions and millions of matches and players. So, again, this is likely your own personal bias, and is not established in the data. You may not be a player that will quit because of this, but others will.

Because of how the ranking system works in lower ranks, it is possible for players of almost any skill to eventually work their way into lower Diamond. It becomes harder and harder, but is still possible, and definitely does happen due to random luck and/or being carried.

It's also very easy in the data to identify which players are which. All we have to do is see which value better predicts whether or not they will win their next match. If MMR predicts whether you win accurately, then it is an accurate judge of your skill. If Rank is NOT predicting whether you win accurately, then Rank is NOT a good judge of your skill. So all we have to do is check which of those two more accurately predicts whether or not you will win, and we know whether or not you belong at your rank.

In addition, like I already said, the data also show that if we give players matches that are too difficult given their MMR, regardless of what their rank says, they are consistently more likely t...

Fortunately, players in a 5q will not get inflated MMR, that's one of the improvements to the system. So when they go back to solo queue, they will be matched near their MMR still.

We are actively working out improvements to the current premade situation, though I don't have anything to announce at this time.

But, yes, we are very aware of how it currently is working.

OK, I'd need more info to pull the exact match, but a Master partied with Diamonds will be considered a Diamond party.

Emerald players can match +1 (Diamond) and -1 (Plat). So if you match with an Emerald, you can also see Plats.

In addition, if you are in a duo, you can see Golds if this happens:

• high Gold duo with a high Plat will be considered a Plat team
• Emerald soloQ player can match Plat (-1) and Diamond (+1)

So you have a Gold on your team, but they are partied with a high Plat, and that party is, on average Plat.

Are you in a party? And this is Ranked?

Yeah, this is where things get tricky again. The Ranks in Diamond+ are skill-based, and in any skill-based system, players will eventually ramp up into a wall once their Rank starts to approach their actual skill. The trade-off happens in balancing the steepness of that ramp against the integrity of the Ranks themselves.

In an ideal system, players realize they are ramping into that wall and know the only way up is to play better than they have been. If they actually do play better, the system should raise their MMR, with the Rank following. So players feel the system is good because it recognizes them actually improving in skill. They then go repeat the process as far as they can. Eventually though, most players will come to a plateau that they won't pass without getting to an incorrect Rank, and ruining the integrity of the system. Once players hit that plateau, they have to decide to keep playing or not. Hopefully they just play because the game is still fun and they enj...

Yes, this is a good point and one we are actively discussing. FYI, the following info is how VP gains have always worked, long before I joined the team.

Currently VP gains are based on the distance between your current Rank (tier, subtier, and VP) and the average MMR of players that also have your same rank. This is because MMR predicts who will win far better than rank does (10-15% more absolute accuracy, which is pretty significant).

So if your MMR is the same as everyone else around your Rank, then you will earn around +/-15.

If your MMR is lower than others around your rank, that can drop to +10/-15 if other players have an MMR much higher. In Masters/GM/Challenger, this can drop to +10/-20.

If your MMR is much higher than most around your rank, you can go up to +15/-10 in Diamond, and +20/-10 in the higher Ranks.

There is also a minimum MMR bar for Diamond. Basically, we say, "We want Diamond to start at the top X% of players by MMR" Ho...

So MMR is equivalent to taking a player's win rate, and then modifying it according to how difficult their matches have been. So in most cases, win% is redundant in the presence of FFA MMR and would just slow MM down. In cases where they disagree, (e.g. 48% win% but high MMR), MMR correctly predicts the winner making the low win% is misleading. Of course if both are low, then the player plays poorly as expected, but that makes it redundant again. Likewise, players with higher win% (e.g. 52%) but low MMR tend to play much worse than their win% would have suggested, which disappoints folks in general.

I think the problem you are running into right now is tightening just how low of an MMR player you can have in your match, even when they are close in Rank. That's something we are investigating.

Oh, also, sorry, I realized a made an major edit after posting the longer message above, so re-reading it may make some things more clear.

We have found that winrate is ironically not that accurate at predicting whether players will win future matches. They do have some correlation, high-MMR players do tend to have high winrates. But we also have plenty of low-skilled players who played in, e.g., 5qs and have higher win rates than you would expect for their actual skill level.

So we use MMR instead, which is actually very accurate at predicting whether a player will win a match, and play as good as their teammates. Though, keep in mind, every player tilts within about +/-1 ranks from their actual rank during any given match. But, yeah, if MMRs are close, you will probably be happy with them.

Yeah, I totally agree that it is better to have players as close to your skill as possible on your team.

Improving this requires tightening the allowed player to player skill gap, making it more likely that each other player on your team (and in the whole match in fact) is closer to you in skill.

This is something we are actively working on. One trick here is that wait time grows exponentially with this particular gap. So it becomes not a question of, "I'm willing to wait another 10 minutes" but instead another 60-120 minutes (as I mentioned in a previous post). Especially when you need to find 10 players at the high end all close in skill.

To deal with this, the current system detects real-time availability and tries to give you the closest 10 possible players. So sometimes, it can make very tight matches. At other times, the system gives up because it knows that even after 20 minutes, the match quality will be the same. We do have some settings within thi...

These are valid concerns.

1. In the data for the last month or so, I don't see Golds ever in matches with Masters. There was a window where we were testing the matchmaking parameters overall and did allow that, but we have since closed that off. Do you know when you saw that? If you have a date and screenshot so I can pull the match, I can look. So far every example I've looked up was legitimately within the rules. The only strange matches that happened involved a trio where 2 higher-ranked players brought in a lower one, stretching the gap.
2. We are aware of how stacking is affecting both fairness and the leaderboard and are actively considering solutions. On the one hand, players in 5q are pretty happy at the moment because ("having the most fun I've ever had in WR!"), which we don't want to take away, and they only match other 5q parties. However, we also know they often have the potential to climb faster than solo queue because of higher win%. We are investiga...

If the anchor is Emerald, they can match -1 (Plat) and +1 (Diamond) so you can see Plat to Diamond in the same match.

A GM anchor can match high Emerald ( I only) to Challenger so you can see Emerald I to Challenger in the same match.

Other combinations require parties since a party's rank is the average of its members.