[G] Comprehensive SC2 League and Ladder Guide - Page 27

On June 15 2011 15:18 enderwiggnz wrote:
If I could make a suggestion to the OP:

Blizz stats indicate 40% in Bronze, not 20%. I believe this group is not included in a standardized curve that makes up the rest of the ladder, as the skew would be too great.

and there seems to be something very "off" about the ladder right now. why they can't use an established system and not screw with it is beyond me.

On June 15 2011 16:18 Mip wrote:
The OP seems to be a lot based on guesswork and is grossly oversimplified, doesn't really seem to match my understanding of how it works based on my conversations with Blizzard.

The MMR is based off of a Bayesian hierarchical model that is extremely volitile (you wouldn't want to see how much it varies based off of the performance of other players you play against) but the idea that your points "drifts" toward your MMR is at best a simplification. I would recommend instead thinking of your relative adjusted points as a crude approximation of your relative MMR.

MMR by it's nature (Bayesian) isn't something you take a moving average of, and it's not a single value. The MMR is defined fully by it's mean and variance (uncertainty) and it represents the whole of systems current knowledge of your skill (sort of, the fact that they boil it down to mean/variance is a simplification of the available information, but it saves them on computation time).

The idea is that they want to measure your "skill", but that can't be measured directly. So the system gathers information from your wins and losses and gets a better and better idea about your skill, but it also retroactively adjusts and learns from performance of the people you win and lose against. It then assigns everyone an "MMR" based on the most probable combinations of mean/variances that would produce the ladder results that are observed.

Basically, points are pretty meaningless, and only very roughly resemble what the system thinks about your skill. The background system is very sophisticated, but it doesn't lend itself well to public reporting. The point system is a feel good shell over the smarter more volatile seeming internal system.

On June 16 2011 01:09 shadowboxer wrote:
I'm curious about something Excalibur said earlier on streaky play. I've been placed diamond at roughly mid-high masters MMR for about 6 months now, but I'm extremely streaky. Sometimes it's an off day, but I refuse to sit that day out and continue to play through the badness. As a result, there's been two times where I was winning 80% one day and about 25% the next. It's not nearly as on and off as it sounds, it's more like I was doing really well 3 days and then tanked 1 day and went back to doing well the next 3 days.

My question pertains to the fact that I've heard you say streaky play leads to the system never having confidence in promoting you. How much of an extreme is this? Every time I reach high master MMR and then lose a bit of it, is it putting me even further away from being promoted? I've literally been high master MMR before I'll start losing consistently and get no promotion. The matches are considered even or I'm slightly favored(against lower rated masters). Is this a result of streaky play? Is the system setting my promotion back even further every time my MMR goes extremely high and then really low, and then back high again? I have a feeling if I bought a new account I'd have no problem getting to masters currently, but I don't really want to have to spend the $60.

It wouldn't matter so much if a lot of tournaments didn't start requiring you be masters. I understand why they do it but it puts people who're getting screwed over by the ladder in a horrible position.

On June 16 2011 02:01 aksfjh wrote:


How recent have you been facing high masters? Battle.net has been acting really finicky in regards to promotions in the past month due to various bugs and various attempts to fix the same bugs.

However, essentially, even if it doesn't have enough "confidence," you should eventually hit a point which your MMR is just too high for it NOT to promote you.

On June 15 2011 16:18 Mip wrote:
The OP seems to be a lot based on guesswork and is grossly oversimplified, doesn't really seem to match my understanding of how it works based on my conversations with Blizzard.

The MMR is based off of a Bayesian hierarchical model that is extremely volitile (you wouldn't want to see how much it varies based off of the performance of other players you play against) but the idea that your points "drifts" toward your MMR is at best a simplification. I would recommend instead thinking of your relative adjusted points as a crude approximation of your relative MMR.

MMR by it's nature (Bayesian) isn't something you take a moving average of, and it's not a single value. The MMR is defined fully by it's mean and variance (uncertainty) and it represents the whole of systems current knowledge of your skill (sort of, the fact that they boil it down to mean/variance is a simplification of the available information, but it saves them on computation time).

The idea is that they want to measure your "skill", but that can't be measured directly. So the system gathers information from your wins and losses and gets a better and better idea about your skill, but it also retroactively adjusts and learns from performance of the people you win and lose against. It then assigns everyone an "MMR" based on the most probable combinations of mean/variances that would produce the ladder results that are observed.

Basically, points are pretty meaningless, and only very roughly resemble what the system thinks about your skill. The background system is very sophisticated, but it doesn't lend itself well to public reporting. The point system is a feel good shell over the smarter more volatile seeming internal system.

On June 16 2011 01:09 shadowboxer wrote:
I'm curious about something Excalibur said earlier on streaky play. I've been placed diamond at roughly mid-high masters MMR for about 6 months now, but I'm extremely streaky. Sometimes it's an off day, but I refuse to sit that day out and continue to play through the badness. As a result, there's been two times where I was winning 80% one day and about 25% the next. It's not nearly as on and off as it sounds, it's more like I was doing really well 3 days and then tanked 1 day and went back to doing well the next 3 days.

My question pertains to the fact that I've heard you say streaky play leads to the system never having confidence in promoting you. How much of an extreme is this? Every time I reach high master MMR and then lose a bit of it, is it putting me even further away from being promoted? I've literally been high master MMR before I'll start losing consistently and get no promotion. The matches are considered even or I'm slightly favored(against lower rated masters). Is this a result of streaky play? Is the system setting my promotion back even further every time my MMR goes extremely high and then really low, and then back high again? I have a feeling if I bought a new account I'd have no problem getting to masters currently, but I don't really want to have to spend the $60.

It wouldn't matter so much if a lot of tournaments didn't start requiring you be masters. I understand why they do it but it puts people who're getting screwed over by the ladder in a horrible position.

On June 16 2011 03:22 Excalibur_Z wrote:


In the first version of the ladder, it was possible to literally be "too good" for a promotion because it would wait and see where you stabilized before you got moved into a new league. Somewhere along the line (around January) they changed it to more aggressively promote people by simply promoting you into the highest tier of a league if you outperformed that league. In this way, you'd at least be able to see some progress via a temporary promotion rather than getting frustrated then suddenly jumping 3 leagues.

On June 16 2011 03:22 Excalibur_Z wrote:


In the first version of the ladder, it was possible to literally be "too good" for a promotion because it would wait and see where you stabilized before you got moved into a new league. Somewhere along the line (around January) they changed it to more aggressively promote people by simply promoting you into the highest tier of a league if you outperformed that league. In this way, you'd at least be able to see some progress via a temporary promotion rather than getting frustrated then suddenly jumping 3 leagues.

On June 16 2011 11:41 Haneul wrote:
Thanks for this post Excalibur_Z, it's super well-written and informative.

Lately though, the ladder seems really weird. I get matched up with people from all leagues. Also I've kind of been on hiatus from SC from a while so my bonus pool is pretty big, how small do I have to get it so that I can change leagues?