Heroes of the Storm news » Matchmaking Improvements: Phase One

When Heroes of the Storm matchmaking was originally implemented, it was based on the system we used for StarCraft II. This works great for a game that’s primarily centered on 1v1 play, and StarCraft II matchmaking has historically been pretty solid. However, Heroes is team-based, and we had to create several rules, such as team composition and party size restrictions, to help tailor this system to a 5v5 game. The more rules that we added, the more difficult it became for the matchmaker to put together high-quality games. While the majority of games that the previous matchmaker put together were reasonably fair, the system still wasn’t quite hitting the mark as often as we had hoped.

At BlizzCon, we spoke about our plan to refactor the Heroes of the Storm matchmaker by the end of the year, and discussed many of the changes this would include. Over the past couple of months, we’ve worked to completely rework the matchmaker in order to bring you a brand new system built specifically for Heroes of the Storm. We’ve seen very positive results after running extensive internal simulations on the new system, and we’re thrilled to let you know that we’ve already brought the initial version of the new match builder to the live version of Heroes of the Storm! Now that the new system is in place, we’d like to walk you through some of the major changes we’ve implemented so far.

Creating High Quality Matches

During our investigation, we dove deep into the heart of the Heroes matchmaker to study extensive live data gathered from all possible matchmaking scenarios. We emerged with a much better understanding about why the system was underperforming in some areas, and what improvements we needed to make. We then set about making changes, with our primary focus set squarely on creating a new system that will consistently provide you with evenly matched games, in which both teams have an equal chance to win.

As a result of these changes, the Heroes matchmaker will now much more effectively group you with allies and opponents that have very similar matchmaking ratings (MMR) to your own, creating games that are fair for both sides. This will also affect Ranked play, and you may notice that all players in your Hero and Team League games are much closer in terms of Ranking. While initial data from live games indicates that we’re well on our way to accomplishing these goals, we’re going to continue monitoring the new system and make additional improvements as necessary.

Queues and Wait Times

The previous matchmaking system would work to immediately put a game together once a player’s wait time in queue reached the ten-minute mark —whether or not the players it selected for that game were equally skilled.

Rather than trying to get you into a match as soon as possible after a certain time has elapsed, the new matchmaking system’s primary focus is to give you the most evenly matched games that it can. If a close game cannot be created, you may be held in the queue a little longer until other players with similar MMRs are found, and a quality game can be formed. What’s more, the matchmaker will now give higher priority to those who have been waiting the longest in queue. This means that you may end up waiting a little longer for a game from time to time, but you’ll have a better match as a result.

Additionally, if the matchmaker believes your wait time will be excessive, it may expand its search to include players who are slightly above, or slightly below, your matchmaking rating. This will help the system find you a match more quickly, while still working to create a relatively even game for everyone it brings together.

It is important to note that these situations are unlikely to affect most players, but may occur for those at the extreme ends of the MMR spectrum when searching for a match during off-peak queue times.

Matchmaking Changes for Parties

The previous matchmaker would try to always match groups of players according to party size. This could become detrimental if a party of similar size and skill could not be found, because the matchmaker would then pull in an opposing party that may have matched in size, but didn’t necessarily measure up in terms of MMR. While new matchmaker will continue to match parties of equal size against one another, we’ve placed additional emphasis on matching teams of similar skill. This means that you may occasionally encounter party size differences between your team and your opponents, but the match you receive will be much higher quality.

To add to this, matchmaking will now also take a party’s ability to more effectively coordinate as a team into account when creating games. This means that if you queue alone and get matched against a party, that party will likely be of lower average skill than your team of solo players, which should help to balance out your opponents’ communication advantage.

Finally, the new matchmaker is capable of relaxing its standard team composition rules to help parties with unusual hero makeups —such as four specialists— more easily find a good match. In some cases, the matchmaker may even attempt to match two parties with unusual team compositions against one another. However, these situations will only arise if the resulting game will be a high-quality match in terms of skill.

Loading Screen Changes

Loading screens may not have anything to do with matchmaking, but they do directly communicate who you’re matched with and against before every game you play. Despite this, we found that loading screens could do a better job communicating this information and decided to make a few adjustments.

Our first change to loading screens focuses on players’ portrait borders, which will now always match the game mode that they are loading into. This means that in Hero League games, you will only see players’ Hero League borders and ranks on loading screens. In Quick Match games, you will only see basic portrait borders and player levels. This should help reduce situations where players could conceal their Hero League rank, for example, behind their player level or Team League rank.

We’ve also added new party icons to loading screens that will indicate which players are partied together, and how many parties are in a game. Despite this first phase of matchmaking improvements, it’s still possible for new or low MMR players to be mixed in with veteran or high MMR players by partying up together. With this change to loading screens, it should now be easier to understand how a low-rated player managed to find their way into your game.

Known Challenges and Future Improvements

In addition to keeping an eye on the changes we’ve made with this first phase of matchmaking improvements, we're looking forward to working on other areas going forward.

• Matching Veterans and New Players
  • We’ve reduced the likelihood that new players will be matched with or against veteran players, but we’d still like to make further changes in this area with future updates.
• Mixing High and Low MMR Players
  • We’ve reduced the likelihood that high and low rated players will be matched in the same games, though our first round of improvements isn’t perfect, we believe we’re on the right track. As mentioned above, it’s also still possible for this to occur when high and low MMR players queue together in parties.
  • Additionally, we’re planning to work on improving the accuracy of matchmaking ratings as a whole so that the matchmaker’s estimations of players’ skill levels are even more precise.
• Quick Match Team Compositions
  • We’ve just added a new rule for Warriors in the Quick Match queue. This functions much like the Support rule that came before it, in that teams without a Warrior hero will no longer be matched against teams that do have a Warrior. Keep in mind, however, that this rule can still be broken by players in full parties.
  • We still have more work we’d like to do to limit unfavorable team compositions in Quick Match. For example, we’d like to limit the likelihood that one team will receive multiple “special” heroes, such as Cho’gall, Abathur, and Nova, in a future update.
• Queue times
  • While queue times have increased as a result of our latest matchmaking changes, the number of quality matches we’re seeing has also increased. We’re going to work toward bringing queue times down, but our primary focus is going to stay centered on providing high-quality matches, and we don’t want to sacrifice good games for shorter wait times. We’ll keep you updated as we make progress toward this goal.
• Matching with Blocked Players
  • We have heard your feedback that it’s not fun to be matched with players that you’ve added to your Blocked Communication list, and while we agree, we haven’t yet addressed this. However, it is on our radar, and we hope to work toward a solution in the future.

The matchmaking changes that we’ve implemented are still brand new, and none of the issues we’ve discussed here today are 100% resolved. This means that while match quality in general has improved quite a bit, it is still possible to receive an unfair game from time to time while we continue to work on further adjustments. It’s also possible that bugs in the new matchmaking system are yet to be discovered. If you happen to encounter any matchmaking issues, please head over to the official Heroes forums and let us know about your experience. Your reports will help us resolve bugs more quickly, as well as investigate unfair matches so that we can continue to strengthen the matchmaking system.

This is only the beginning of the changes we have in store for Heroes of the Storm matchmaking, and providing evenly matched games is still our highest priority. We’re going to keep monitoring data from live games, and will continue to make improvements with future updates. As always, thank you very much for your feedback on the matchmaking system over the past few months. We hope you’ll continue to share your thoughts with us going forward.