In recent months, we’ve seen many discussions regarding the StarCraft II ladder. We wanted to make this post to detail the ladder changes we have planned for the next few seasons and beyond.

First, we’d like to catch everyone up to speed. We’ve seen a lot of valuable discussion from the community regarding the StarCraft II ladder, and we’d like to provide clarity concerning the top issues being discussed.

League Distribution
We’ve seen many reporting potential inconsistencies with league placement across all regions. Last year, we made league boundary adjustments that helped balance overall league distribution percentages. With league distribution being affected by the amount of players participating in ladder and their level of activity, we mentioned at the time that a similar adjustment may be necessary again in the future to help maintain our desired target percentages. After reviewing the league distribution percentages, we found that our target percentages were indeed inconsistent with our desired values.

“MMR Decay”
In a previous ladder update, we mentioned that we’d take a look at how ladder was being affected by what players call “MMR decay.” This is the slight adjustment to a player’s hidden rating that occurs after a player has been inactive for a certain period of time. During our analysis, we found that this feature was helping create even matches for players who were coming back from breaks and looking to ease back into StarCraft II. During our more recent ladder analysis, we found that while this feature is still helping many players, there are situations where it’s not having the desired effect.

New Player Experience
We’ve also seen many new players express concerns that their placement on the ladder is too high for their skill level. After investigating, we’ve found that the default starting point for new players had slowly shifted over time. As such, the entry MMR for new players is now representative of a much more skilled player than was initially intended.

Other Factors
As we’ve gathered more data over the years, our analysis has allowed us to more precisely understand how various factors affect league placement and matchmaking over time. As part of this, we’ve identified a few internal functions that we feel can be adjusted or removed to improve the overall experience and allow for more consistent matching with evenly skilled opponents.

While investigating these areas, we also took a careful look at player win-rates. When looking at players who are consistently active on the ladder, win-rates are right around 50%. However, players who are playing only a handful of sessions per season may be seeing less accurate matches, due to both a less measureable skill level, and also due to some of the topics discussed above. With all of these things in mind, there are a number of changes that we have arranged to roll-out in the coming future.

Upcoming ladder changes for this season
With the season partially complete, we’d like to ensure that any immediate changes to the ladder will not have a high risk to impact existing data from this season. Taking this into account, we identified a couple of changes that we feel will have a positive impact on the ladder in the current season.

Adjust league distribution
As mentioned, we’ve identified that the current league distribution percentages aren’t in line with our target percentages. The upcoming distribution changes should allow many more players to be in the correct league, and for each league to have the correct percentage of players based on the figures we announced for Heart of the Swarm. Once this adjustment is made, some players will see a change in their current league placement.

Adjust the starting point for new players
Due to the dynamic behavior of the StarCraft II ladder, we also saw that the new player starting point had drifted over time. This resulted in new players facing higher skilled opponents than in previous seasons. Adjusting the starting point for new players should improve the new player experience as they’ll be initially matched against lower league opponents once again.

Upcoming changes for next season
Beyond the changes in the current season we also have a few other changes we’d like to implement in the upcoming season. Some of these changes are bit more drastic, so we decided to implement them when Season 2 rolls around in the coming weeks.

Disable “MMR decay”
Starting next season, we’ll be disabling this feature and continue to investigate potential improvements to the system. While we’ll lose some of the benefits that this system provides, we feel its removal will also provide more clarity into player skill level for the upcoming seasons.

Adjust other internal functions that affect matchmaking
As previously mentioned, we’ve identified changes to internal functions which can help offer a more accurate and consistent matchmaking experience. While these adjustments may not be immediately obvious to players, they should help keep the ladder system more stable and consistent over time.

Re-adjust league distribution percentages and the starting point for new players
We’ll also look to once again adjust league distribution and the new player starting point in the upcoming season. This will help them remain accurate after these other adjustments are made.

Upcoming changes around Legacy of the Void
While we expect that the changes above will have a significant impact on how the current ladder functions, we’re also looking to make more changes in the future.

Re-evaluating the ladder system
In the longer term, we’re looking at what other changes can be made to the ladder around the Legacy of the Void time frame. This may include keeping some elements that we feel are working from the current ladder system and overhauling elements we feel could be improved. Our goal here is to ensure that the new system is more accurate and offers more transparency into player progress. We’ve seen feedback on desired changes for the ladder recently, and we’d encourage everyone to keep sharing their thoughts.

We appreciate all of the feedback we’ve received from the community on this topic. We understand how important is to everyone and we’ll continue to focus on ways we can improve the ladder experience for everyone.