One of the many tools that are used to assess balance in StarCraft II are the relative win rates for each race versus the others called adjusted win percentages. What's an adjusted win percentage? While the math behind calculating an adjusted win percentage is extremely complex, an adjusted win percentage can be summed up as the 'true' win percentage of a given race, produced by removing the skewing effects of the matchmaker and factoring in player skill. Combining information from millions of games being played, hundreds of thousands of players, their hidden skill rating, and a little math, we can generate reasonably accurate figures to compare how successful each race really is versus the others.
We can then categorize these stat by league, region, specific stretches of time, or any other way we might want to arrange the data for analysis. The end result is the information that we use (in combination with many other resources) to piece together a picture of what current StarCraft II balance looks like.
Before you review these numbers, we'd like to explain what these ratios mean:
These numbers aren’t static. They shift almost constantly with the metagame as newly discovered strategies spread through the community, and that heavily influences how they’re interpreted. Also, due to the way the math works out we will almost never see ratios of 50:50; we expect a variance of +/- 5% in these results. So, if a win/loss ratio is approximately 55%:45%, this would indicate that the matchup is well balanced—we expect those numbers to fluctuate within that range to some degree. Ratios just outside of that range are still within acceptable boundaries. It is only after win/loss ratios exceed 60%:40% that there is an indication that a potential imbalance might exist. We keep a sharp eye on these variations from day to day and week to week, staying constantly alert for where the numbers are changing and what the possible causes could be. It’s fairly common, for example, for a new strategy or build order to skew the numbers in favor of a particular race for a brief period, until the metagame catches up and the counter strategies spread through the community. Sometimes it’s possible to see this effect reflected in the balance numbers from region to region. A good example in this snapshot are the differences between the win/loss ratios for the Master/Grand Master Leagues in North America and Europe versus the same leagues in Korea.
Still, while they may be interesting, it’s important to emphasize that these numbers aren't the last word in our balance analysis. It’s easy to make too much of them, and there’s a lot more that goes into balance analysis. It's best to consider stats like these as a point of interest and one step along the path to fine tuning balance, rather than the final destination.
Now that you might have a clearer idea regarding what they are, we'd like to share some recent adjusted win percentages from September 13th 2011 for North America, Europe and Korea.
|All leagues||North America||Europe||Korea|
|Master + GM only||North America||Europe||Korea|