Apr 12, 2017
Hello again, everyone! Today I wanted to talk about a behind the scenes change to our matchmaking systems that just went live with the 1.10 patch, but first I should take a step back and provide some background information.
As Jeff Kaplan noted in a recent post about smurfing, we do a decent job of quickly determining someone’s skill at playing Overwatch. The faster we can update your matchmaking rating (MMR) to match your “real” skill, the fewer unfair matches get created with a player with inaccurate skill. Another way to look at it is that when we’re incorrect at identifying someone’s skill, then win or loss streaks can occur. One of the tools we use to accelerate a player to their appropriate MMR is a multiplier to the rating change based upon these consecutive wins or losses.
While this streak multiplier has been working well in the “smurf” case, win or loss streaks can also just naturally occur when the matchmaking system has already properly identified skill. After all, the matchmaker is trying to place in you fair matches where you have a 50% chance to win. It’s rare, but sometimes you flip a coin 5 times and it lands on heads every time. So, when these natural streaks occur, the multiplier has been accelerating gains and losses away from your “true” skill. You end up having a larger variance in skill rating over time, which in turn hurts the overall quality of the matches.
Therefore, we’re changing the tuning of the streak multiplier to be quite a bit less aggressive. You now need to win or lose more games in a row before any multiplier is used, and it scales up at a slower pace. Furthermore, we will now try to only use the multiplier in cases where the matchmaking system has some confidence that the player’s MMR and skill are wildly mismatched. In cases of natural, random streaks, you ideally shouldn’t see any acceleration either up or down at all.
We’ll be monitoring how these changes affect overall match quality going forward, and continue to adjust tuning over time to improve the fairness and quality of Overwatch matches. Thanks for the continued feedback, and good luck in your matches!