1) Why average race mmr = data balanceWe saw many ways to calculate balance in the past. Some can be indicators some are total useless.
Win/loose statistic of pro players was often used because they are easy accessible and can indicate balance problems.
However, this data dont take into account how strong the players are depending to each other.
The Skillfunction behind MMR is invented to do exactly this.
Arguments like "Race x players are stronger than race y players" are invalid because if this is the case we can call this already imbalanced.
2) Why mistakes in the MMR calculation don't affect the result or affect itFirst: the accuracy of my mmr calculation is very good. But i can be wrong in some points or for some users.
However nothing in the calculation takes the race into account.
Theoretical it can be that my mmr calculation is race biased without even knowing the race.
However at the moment i dont see any indicator for that. But i will watch it closely
3) Why race populations dont change the result.Because i take the average. This point is obvious but i better point it out.
4) Statistic independenceif you take the average of the race you must make sure that you don't have and depending factors in the data.
So what can be such a factor:
1) race/skill distribution of the user-group of my program is not representing battlenet user group
There is no reason why 1. should be true.
Also the data includes to 96% the opponents of my users and only to 4% of the users himself.
So the data have a random user base.
so we can exclude point 1.
2) Skill-range of my users is not skill-range of the battlenet
The users of my program have a way higher average skill than the bnet usergroup.
Also the opponent is allways in the range of the user.
So point 2 is true!
We have to remember that our result is not valid for the hole ladder, its only valid for our skillgroup.
Diamand, Master and Grandmaster are overrepresented in my usergroup.
This means this data show the balance on higher skillevels!
5) prove of small deviation and significancelolcanoe make a nice analyses of the data. thanks for that!
On July 13 2012 07:41 lolcanoe wrote:US DATA ONLYTerran Average MMR, STD
1559.214909, 546.131097
Protoss Average MMR, STD
1620.764863, 509.5809733
Zerg Average MMR, STD
1672.129547, 495.3121321
TWO SAMPLE T-TEST RESULTST-Stat, T vs Z T-Stat = -5.693
P = .0000001386
T-Stat, P vs Z T-Stat : -2.872
P = 0.00472
T-Stat, T vs PTstat = -3.03
p = .00238
Histogram of T MMR for normality check:
![[image loading]](http://i.imgur.com/FNzvx.png)
Anderson-Darling Test for Normality (T only)
![[image loading]](http://i.imgur.com/7kVqA.png)
With a p slightly greater than .05, we cannot reject normality of the data. However, the weakness of this statistic indicates that normality should be scrutinized in the interpretation.
Assumptions- MMR is an independent, fair indicator of skill.
- MMR is approximately normal.
- There is no sampling bias between races, however there is a sampling bias towards higher average skill.
- Cause-effect cannot be established by this test.
With over 99% confidence, we can reject the null hypothesis that the averages are equal in all 3 matchups. This is not surprising given the quantity of data, in addition to a maximum 7% difference between T and Z in average MMR.
The data for T appears approximately normal, but the study does not conclusively show that MMR is normal.
6) Because some people have a problem understanding this:
-I calculate the unbalance of skill not the reasons for this unbalance!
-I calculate the average skill of an race not the general popularity of an race
7) Data:
Datafile