Discussion on MMR system

I don’t know if you are sick and tired of this discussion. Just if you are willing to still discuss the ranking systems, it is here.

To begin, I agree that there is no dual ranking system.

The decay system puts me in D5 while my true hidden mmr doesn’t decay. This is why I get multiple 500 pts every time I’m jumping into SL again.

The same observation can be seen by dodging draft 2 times in a row. You’ll get the 600 (or 500?) pts back, but not the full 1.2k with the loss forgiveness system. Meanwhile, your hidden mmr won’t change and that’s why you’ll easily get your missing 600 pts portion of it just by playing the game.

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How do you know your hidden MMR has not changed?

I am not sure why this thread is titled as it is, if you could do me a favor and rename it to something neutral such as “MMR Discussion”, I would greatly appreciate it.

Edit: Thanks!

There is an uncertainty built into MMR for accounts that haven’t played for a certain length of time (not sure what that is, though). This applies to any rank, not just Diamond and above where rank decay kicks in. I had taken a month or two off in the middle of a season, and when I came back, I was still at the same rank, but was winning/losing 400-500 points per match. After about 5 matches, it started settling back to the normal 200 points.

It does this for new accounts as well.

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obviously the title is to indicate how hot it’ll get in here. People will be saying some steamy stuff that get us all hot and bothered and whatever other thermo-endo they come up with.

Cuz that hawt, hot, haht

I don’t have the metrics with me, so I’m speaking out of pure speculation. If someone have it, I’ll gladly be proven otherwise.

If you’re true rank is gold and you decide to come back to SL, your win rate will be 50% since the decay didn’t affected you.

On the other hand, being truly 2k master, but decaying to D5, you’ll have around 55%. While having better odds of keeping 500 pts a win in a longer period of time, the 5% is not sufficient to justify itself what I’ve experienced multiple times. I’d get out of D5 in no time comparing to a G5 that hasn’t decayed. It’s like I’m having a better bonus for accounting how high my true mmr really is.

Do non-decayees (weird word) get that 500 pt bonus for the next dozen or so games though? After they return from a very long break. I’m not so sure about that.

I thought it only affects those who get Rank Decay, in other words, players who are above D5.

So the system affects only ~10% of players. It helps severely decayed higher ranks to get back to their original rank faster and retain them as players.

I think a G5 who has not played for a long time wont get that bonus and they have to chug along at 200 pts like others at their rank.

I don’t think so, not 12 games for G5. But, more likely the case for decayed master.

Then again, we’d need some datas over here to confirm it.

I can confirm that I am not, and have never been, at a rank that qualifies for rank decay, and yet I have gotten 400+ point changes after the matches I played after coming back from a break of roughly 6-8 weeks. I think the point is that while your MMR is fixed and public, there actually is a second number that is hidden, and that is, for lack of a better term, MMR uncertainty applied to your account.

The higher your uncertainty, the more points you will win or lose each match, until you have enough matches played for the algorithm to have confidence you are at the correct rank. It is easiest to see this in new accounts. Last season, I introduced a handful of WoW guildies to HotS, and after first going over the basics in AI, we moved on to QM, and some decided they wanted to see how they stacked up in SL. All of them placed in mid to high Bronze. However, for the first 10 or so matches after they finished placements, they were earning 500 points per win, and several of them skyrocketed up to Silver. Being a brand new account, their uncertainty was fairly high, and since all of them had at least basic gaming experience and coaching from me and another guildy who routinely places high-Plat/low-Diamond, they had enough game knowledge and skill to move out of Bronze swiftly.

Another place you can see uncertainty at work is when someone goes on an extensive winning streak, and starts earning more points per win, until they get back to their “true” rank.

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Seems like this factor applies to all returning players then, not only players with D5+. Their MMR uncertainty is basically reset once they’re gone for about 2 months and the system has no idea about their current skill level anymore.

That’s a good feature. It’s also not a free ticket to higher ranks, if that returnee is significantly worse, that works both ways (they will also lose 400-500 per match, which can lead to very quick deranking).

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Exactly, and I do think it is the fairest way to treat new and returning players. As a side benefit, if you do have a GM smurfing their way through Gold, they will likely not stay there very long! I know I encountered a few of the EU pros ranking up in NA SL since they were grinding levels to get their accounts ready for CCL. Although I saw them in Plat matches, they were all in Master+ in a week or two at most.

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OK guys. Let me explain how I understand the MMR system works and let me know if there is something that does not match with what have been said by the dev or what you have observed. I am only talking about the core system here, not about “add-ons” such as rank decay.

As I understand it, there is only one system now, not two as before. However, I think there two numbers that represent the same thing: your position in the lader: 1) your hidden (in the sense that you cannot actually see it) MMR and 2) a couple (division, rank points), rank points which are between 1 and 1000 for each division. They are two representations of the same thing and are mapped as a one to one function.

Now, the dev have posted something about the ranking system a long time ago. There was a bell curve with the MMR points in the x axis and what I assume is the pourcentage of the player in the y axis. They said that typically Bronze 5 maps more MMR points to the 1000 rank points. More importantly, they said that the rank points are points on the bell curve.

So what I beleive is that the only thing that matters is the MMR. The couple (division, rank points) is only there as a representation of the MMR points and everything is actually computed with the MMR.

Now the difficulty is how the MMR and the (division; rank poitns) are mapped, or said otherwise how the rank points are placed for each division on the bell curve. Now I am going to make an assumption: for each division, the rank points are placed so that it represents the percentage of the population which are behind or above you in the division. For example: if you have 250 rank points, there are 25% of the players in that division which are below you.

I also beleive that for each won match, you gain the same amount of MMR points, baring some adjustments. But let’s keep it simple and say it is always the same amount of MMR points.

Now, what does this has to do with what I read about how rank points behaves.

For Bronze 5, if the rank points are placed as I think, due to the shape of this bell curve, the correspondance between MMR points and percentage of the population (and thus rank points) is is “streched” for low MMR in Bronze 5 and is something like this (let’s say the range of MMR is 10 000 even if I think it is unbounded)

MMR Percentage population Rank points
6000 10 100
8000 25 250
9000 50 500

Now if you are low in MMR in Bronze 5, earning let’s say 200 MMR points actually gives you much less rank points. When you are at the top of Bronze 5, you gain the same amount of MMR points but they now reflects to (approximatively) the same amount of rank points.

For the GM case, the effect is the inverse, still due to shape of the curve, and you gain less rank points the more you are in the top of the division.

For the other divisions, the shape behaves well enough so that there is no distorsion between MMR points gain and rank points gain.

Its trash, it will never be fixed, bizzard gave up on it. Next.

Sort of, they go into it in detail here:

As you said, Master/GM is another special case, but that one is easy. The rank points are still based off of 200 per win/loss, but they can just keep tracking points indefinitely. GM is just “those who have the most points”, nothing else.