Blizzard Blog: Balance Snapshot - Page 27

On September 23 2011 21:52 paralleluniverse wrote:

In very simple terms: If you recall conditional probability from school, they calculate the probability of winning conditional on MMR.

On September 23 2011 21:55 paralleluniverse wrote:

I would also add that what they use is from the theory of Bayesian Inference, which is usually taught as a honors year math/stats course at most universities, so you won't understand the fine details of this method unless you have a university-level background in statistics.

However, it is still very possible to understand the overall "big picture" view of what they're doing.

Suppose there are 5 numbered balls in a bag.
1 - red
2 - red
3 - blue
4 - blue
5 - blue

(A) What is the probability of drawing a ball numbered 4? Clearly it's 1/5.

(B) For the balls that are blue balls, what is the probability of drawing a ball numbered 4? It's the number of balls that are both blue and numbered 4, out of the number of balls that are blue, that is 1/3.

Now replace "less than 4" with "winning" and "blue ball" with "MMR equal to, say, 3000", then (A) corresponds to simply looking at unadjusted win ratios and (B) is in principle the method that Blizzard uses.

The idea is to get the probability of drawing a ball numbered 4 when fixing the color of the ball, or in Blizzard terms, getting the probability of winning when fixing MMR, and that's done by taking the probability of both having a certain MMR and winning, divided by the probability of having that certain MMR, i.e. what we did in (B).

Please tell me if my explanation isn't clear, I do actually want people to understand this idea.

On September 23 2011 01:52 Andreas wrote:
Interesting how NA and EU PvZ and TvZ winrates are so much higher than in Korea. Are Korean Zergs really that good?

On September 24 2011 09:31 b0t wrote:
The purpose of this blog post is to convince the community SC2 currently is balanced. The author didn't give a f*ck if PvT is really balanced, he just picked numbers in a way to make it look so.

"There are lies, damn lies and statistics."

On September 24 2011 16:32 Sumadin wrote:


So Blizzard only tells the truth when the truth fits your version of the game?

Serriolsly i am tired of people trying to deny facts everytime blizzard posts some, or try to claim that blizzard couldn't make data out of their own statestics because"Technically the MMR makes all go closer to 50%".

On September 24 2011 20:03 Madkipz wrote:


if they were telling the truth would it not be more thorough?

A map based statistic for instance?

On September 25 2011 00:20 Sumadin wrote:


Well the topic for the blog was to focus on overall race balance not the balance for individual maps.

It is safe to assume through that most of them are within the margin of 60:40 for all races. History has also shown us that blizzard does care for map balance aswell. Jungle basin was removed from ladder mid-season because it grossly favored terran beyond what was acceptable.

On September 26 2011 14:06 hobosrus wrote:
these numbers dont mean anything doesnt blizzard know that it matches people so that their winrate is constantly 50% so if a person's race is imbalanced he will be playing people who are better than him and make his winrate 50% and the game will say that he is evenly matched with these people even if it could just be a racial imbalance.