Player Behavior Knowledge Base > Matchmaking



1. About


Matchmaking is the existing automated process in League of Legends that matches a player with, and against, other players.


2. Implementation


The system estimates how good a player is based on win/loss ratio. It tries to matchmake players in a way that they have a 50% chance of winning [466], to ensure fairness and competition, which is one of the priorities of the system [640]. However, this priority also becomes less and less important the longer a player takes to find a match, which is the reason of existence of the system [640].


Matchmaking takes into account premade numbers, so that groups are usually paired with other groups of similar size [35], especially due to groups being seen as having more advantages than pure solo players (communication and pre-knowledge of each other’s playstyles being factors) [625, 640]. This also determines the MMR of the team being an average of each member’s score, with some increase depending on how many premade members there are, which also involves the risk of getting tougher opponents [640].


Important is to note that MMR differs for each queue [640], which explains to some extent why players may occasionally meet high rankers in their normal matches.

In ranked, the very fact the matchmaking pool is small for high MMR players forced Riot to release and tune the “autofill” feature around July-August 2016, in order to decrease queue timers [626].


3. Miscellaneous


  • The “Unskilled Player” report was used as matchmaking feedback, not for punishing players [176].
  • Using matchmaking as a “prisoner’s island” to punish misbehaving players is a concept that Riot rejects as “lazy design” that “only encourages further negativity” [218, 393].
  • MMR only depends on win/loss ratio to prevent unwanted behaviours such as players farming up their KDA score instead of ending matches, in addition to the fact that KDA and actual personal skill are very hard to determine and implement in the matchmaking formula [640].


4. Sources

176 ; Page 316
393 ; Page 290
466 ; Page 116

Created by mastermars on 09-02-2017. Last edited: 28-06-2017