/dev: Updates on 2020 Ranked & Matchmaking

We've got details on progress we've made, our next projects, and early preseason explorations.

Welcome back! Again, I’m Cody “Riot Codebear” Germain, Product Lead for Competitive Gameplay on League of Legends.

In late February we talked about our plans for Ranked in 2020. Today we'll revisit those goals, provide an update on what we've done so far, and reveal some big changes that are making their way to you soon. Buckle up!


As a refresher, this year we want to solve problems that have been a thorn in everyone’s side for years. This means picking apart our systems and yanking out old plumbing to meet the following goals:

  • Improve queue matchmaking quality without compromising queue time and availability.
  • Improve transparency around ranked and matchmaking systems.
  • Improve progression satisfaction and skill expression in our systems.
  • Make rewards more recognizable and relevant for time spent in League.
  • Players can play with, and find, others they want to play with.

Last post we briefly touched on 'Game Ruining Behavior,' but didn’t explicitly include it in our goals. As such, we've added a new goal that explicitly covers the interactions you have with other players during your matches:

  • Provide players who are subject to bad behaviors more visibility into actions taken.

Initial Results

We’re about a third of the way through the year. Our focus so far has been on our first goal: Improve queue matchmaking quality without compromising queue time and availability.

Here's what we’ve shipped since February and how it’s faring:

Autofill Parity: In 10.6 we shipped Autofill Parity, which aims to equalize the number of autofills across teams. Since then, autofill imbalance has gone from 11.4% of all ranked solo/duo games to less than 5%, with almost no impact to queue times.

Autofill Swap: Players helped us find a gap where autofill wasn't accurately accounting for teammates' role preferences. This led to situations where two teammates were autofilled into each others' primary or secondary roles. In 10.7, we completely eliminated that bug with no impact to queue times.

Premade Parity: Similar to Autofill Parity, Premade Parity strives to make matches with an equal number of premades on each side. We activated this feature in 10.7, and since then we’ve gone from 54% of premade matches having imbalanced premades to 6%, with little to no impact on queue times depending on skill level.

New Matchmaking Algorithm: Over the last few months we’ve been simulating and testing a new matchmaking algorithm to more accurately and quickly identify new and veteran player’s skills. We’re happy to say that we finally made the right changes to outperform our old system and made a full upgrade to normal queues in 10.10. The system is showing an improvement in most regions (measured in terms of win prediction accuracy) and has allowed us to be confident in moving forward with our next feature: Ranked Account Seeding. 

The new matchmaking algorithm will be finding its way to ranked queues in early preseason to avoid major impact to ranked MMR during the current season.

Ranked Account Seeding: Formerly known as “New Account Seeding,” Ranked Account Seeding is built to more accurately place you in your first games of Ranked. In the past, we were using a fixed placement to start you somewhere towards the bottom half of the curve. While starting everyone at the same spot was "fair", this meant players actually at the skill level of the starting MMR were frequently matched with new players whose actual skill was much higher or lower. Since MMR is close to a bell curve, this meant matchmaking quality suffered right at the highest-populated skill level. 

By seeding players based on gameplay information from other queues, we’re confident that players will be more accurately placed at the start of their climb. This will make it so others aren’t experiencing matches that seem imbalanced from the start. We’ll be rolling this out slowly over the next couple patches so we can monitor and respond to impacts quickly and carefully.

What’s Next for Matchmaking

We’ve made a lot of improvements to matchmaking over the first third of the year, and the team is rolling onto work toward our other goals. We’ll still be monitoring matchmaking and will make additional tweaks as necessary, but investigation on remaining topics like autofill position parity (both teams have the same positions autofilled) and Blue side/Red side matchmaking calibration will be on more of a preseason timeline.

Coming Soon

Our next major area of focus is on providing better feedback on action taken around disruptive behaviors. We've already begun shipping improvements:

Player Feedback: In 10.10 we started leveling up our Player Feedback system's notifications and actioned punishments will be much clearer going forward. You're now notified when disruptive behavior you've reported is punished, even if the player was punished for a different report category or in a later game. Let us know what level of feedback feels right to you as we experiment with these notifications. We’ll be actively tweaking the visibility configurations here to make sure we find the right balance on punishments.

Where are we now and what’s next?

We think one of the best ways to identify and implement the right solution is to iterate quickly and adapt. Throughout 2020 and into 2021, we’ll be experimenting with some new features on live servers to more rapidly adapt to behavioral trends as they come up. Compared to full fledged features, you should expect these experiments to be less developed, but evolve rapidly if we see clear successes. The goal is to get quick feedback from players as we're rounding these features out so we don't waste time and resources on things that won't actually solve the problems you're dealing with.

Here's the first area we're exploring that clearly isn't meeting today's standards:

Champ Select Reporting and Muting: Disruptive behavior in Champ Select is a problem that players have very few ways to deal with. Starting late June/early July we're going to give you the ability to report a player in Champ Select. At first, these reports will be used to establish a data foundation for champ select behavior. Once we've got a solid understanding of the situation, we'll be looking to build out a punishment system. Of everything we're talking about today, this is the one we're going to be most cautious with.

What’s Next?

Given the breadth of this space, we’ll be looking into next steps around game-ruining behavior throughout the year. Additional communication around this can be found in Meddler’s most recent blog post. We'll provide more updates soon.

We've also got one improvement tee'd up toward our goal of ensuring players can play with, and find, others they want to play with.

Opening Flex Restrictions:Over the past few months we’ve seen 5-stack premades in Flex queue go from less than 20% of Flex games to greater than 35%, likely due to the launch of Clash and more time at home. This makes full premades the most popular party size in all of Flex Queue. There's no better time for us to loosen up the gates and allow players to play with anyone on their team, not just those within nearby ranked tiers. To maintain match fairness, we're switching Flex's matchmaking to be more similar to Clash's which prioritizes balance across a much broader range of MMR. We're currently locking down which upcoming patch to ship these changes in.

Preseason Ideas in Exploration

In addition to what we've talked about so far, we’re also planning more improvements to Ranked for Preseason 2021.

Promo Series: Toward the goal of improving progression satisfaction and skill expression in our systems, it's looking likely that we’ll be removing inter-division promotions to reduce frustration of seemingly hitting a wall when you know you’ve been playing well. This means we'll also need to look at inter-division demotion protections to make sure that players are able to get where they should be in both directions without false limitations.

Ranked Informed Matchmaking and Transparency: Playing matches where displayed ranks are very far apart is frustrating, regardless of how close everyone's MMR is. We’re looking to modify matchmaking to include rank spread limits and skill level transparency updates. The goal here is to give you confidence that you’re playing with other players who are in the same stage of their climb as you are. Overall, we’d like to avoid those occasional situations where you see large gaps between players' ranks in your games.

Rewards and Legacy Recognition: We’ll be making thematic changes to the Victorious line and highlighting your current and past ranked accomplishments so that you can let other players know your past achievements without diluting your current ones.

Organized Group Play: Given the successful launch of Clash and the increase of premades across queues (see the Flex note above!), it’s time to come up with a more cohesive vision for where team-based League of Legends takes us in the future. We’re going to be looking at long-term solutions for:

  • How Clash and Flex play together to create a healthy team ecosystem for League of Legends.
  • Ironing out how you find others in League like you to play with.
  • Recognizing teams that stick together and giving them something to strive for long-term.


It’s been a busy year so far, and the team is super excited to keep the ball rolling and deliver more improvements to your competitive experience. We’ll continue to provide updates on what we're shipping and how things are going, so please keep giving us your unfiltered feedback. As always, we’ll see you on the Rift.