[2022] Diamond LP gains seem to be random

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" However, because of Ranked Fortitude as well as luck, it is possible for players with an MMR below that bar to get into low Diamond. When this happens, your VP gains will consistently be at the +10/-15 mark unless your MMR catches up to the minimum Diamond bar.

We have talked about smoothing this experience out so you don't get immediately pushed out of Diamond, and perhaps not hit the -10/+15 wall until Diamond 3, etc.

The other point here is that the VP gains don't appear to take the match into account. This isn't entirely true, as your MMR can change after each match based on the outcome of the match. If your MMR goes up, then your VP gains will also go up after that match.

We have discussed further augmenting that to more directly take into account things like:

• How difficult was the match: So if a match was really easy, you could get less VP for it. This approach is common in many games.
• What happened in the match itself. Did you over/under-perform? What about your teammates? This sounds fun on the surface, but can be very tricky. It can lead to players trying to optimize whatever will get them extra VP, potentially at the expense of winning. So anything that we did here would have to be something that definitely helps players win.
  

These are common topics and problems within the realm of how VP works.

There are two parts to making Ranks like those at the top effective:

• They try to accurately reflect player skill, otherwise they risk not mattering. This is usually the top priority because players will not care about reaching Master if it's not actually challenging and representative of high skill. To do this, we try and get Rank and MMR to match up well in high ranks because MMR is the most accurate measure of player performance (much more accurate than win% and rank looking at millions and millions of data points). This is what makes sure your average Master/GM/Challenger are solidly good players.
• The player update itself tries to feel intuitive to players after the match. This is an area we know we can improve. We'd ideally like the points you get after a match to feel fair, while at the same time prevent players from just inflating their Rank well beyond who they are actually winning against. This is a constant balance and can be quite difficult. There can be matches where you feel you played really well, but you actually just played exactly like predicted for your Rank. In those cases, it would be wrong to give you a bunch of extra VP because then you would have a higher Rank than players who are just like you. On the flip side, there are also cases where you think you played poorly, but you actually played well above your rank in a difficult match. Ideally we would give you extra VP there that may also seem unintuitive. We have some ideas in this area, but nothing we can chat about at this time.

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 enjoy the higher competitiveness of Ranked instead of Normals.

One way to do make this work is to just throw harder and harder matches at players so they realize they "don't belong," once they get above their Rank. But we have found that giving a player an unfair match is more likely to cause them to stop playing than the wall.

Because of this effect, we instead give players matches at around their skill, which means matches can often feel the same in terms of performance and difficulty even if the player has gotten better or worse. This can make it difficult for the player to know easily if they are getting better or worse.

In addition, for example, sometimes, players randomly luck into their Rank being higher than their MMR. When this happens, players end up still playing matches at their MMR level --- which is below their Rank --- and since their opponents are lower than their Rank (because their MMR is below their Rank) they are given less VP for a win than for a loss.

MMR works for the most part like it always has. After every match it goes up or down a little based on the match. It uses the information from the match that would best predict whether the player is better or worse at winning matches than believed before the match. We have made some changes over time that have made MMR significantly more accurate in the past, but at the end of the day it does a good job at predicting who can win a given match.

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 to quit the game.

Given that information, we know that we need to matchmake players near their MMR, because it more accurately shows how they will perform, and that same system is also valid to use to judge a player's ability.

I mean, that's at the core of what every top competitive game uses for ranking, and MMR-style system that accurately predicts players' ability to win.

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.

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.

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.

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.

• 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!

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 to figure out each player's skill.

Feel free to DM me if you want me to check your MMR.