Matching Markets in League of Legends
League of Legends is a popular multiplayer strategy game where 2 teams consisting of 5 players each fight to gain control of a map. In order to create these games fairly, matchmaking is used to create teams of equal skill to play against each other. Players take this matter seriously as matchmaking inconsistencies create unfair advantages for some teams. There are several way that these advantages surface. For example, “smurfs” are players that create new accounts with a ranking below their true skill level. Teams with “smurfs” often have unfair advantages because the skill level is not balanced between the two teams, despite the matching market appearing as so. To add another layer to this problem, there are five roles in the game commonly known as top, jungle, middle, bottom, and support. Players are usually accustomed to one or two roles because each takes time to invest in and learn. In the scenario where players are matched against each other for a ranked match, some players may be given a role that they are unfamiliar with. This also creates an unfair advantage if one team has an “off-role” player while the other has everyone “on-role.”A player being put into an “off-role” situation is referred to as being “auto-filled” because the player is left to fill in a role that no other player currently fits for matchmaking.
In the context of a matching market in this class, the nodes would be players, and buyers and sellers can be seen as opposing teams. There are several ways that matchmaking resembles a matching market. Firstly, when every player is assigned a role, a situation where every player gets their desired role is a perfectly matched market. When not all players get the role that they desire, this can be seen as a market where there is no perfect match. Interestingly, Riot Games, the developer of League of Legends has employed several ways to “artificially” produce a perfect matching. One of these methods is “auto-fill parity” meaning that if a player on one team is given an off-role, there will be a guarantee that there is a player on the opposing team that is given an off-role as well. This method can be seen as a more “fair” outcome by creating two imperfectly matched markets. Given that it is impossible to always have a perfect matching when it comes to matchmaking in a competitive video game, I found it interesting that Riot Games employed this solution to create more fair scenarios. Usually, perfect matching is seen as ideal in most cases, however, subverting that expectation to create a fair multiplayer experience makes a lot of sense.
In the picture attached, an imperfectly matched market is seen. In this case, the buyers are different roles in the game, while the sellers are players with role preferences. Since every player’s role preference can’t be fulfilled, there is no perfect match for this market, showing auto-fill in action.
An example of auto-fill in League of Legends: creating an imperfectly matched market.
Sources:
https://www.leagueoflegends.com/en-us/news/dev/ask-riot-autofill-in-ranked/
https://support-leagueoflegends.riotgames.com/hc/en-us/articles/201752954-Matchmaking-and-Autofill