TrueSkill

Definition

TrueSkill is a Bayesian rating system developed by Microsoft Research for Xbox Live, used in Halo, Gears of War, and Forza. Unlike Elo, TrueSkill models each player as a normal distribution with a mean (skill estimate) and standard deviation (uncertainty). It supports multi-player teams natively, which is why it works well in 5v5 and 6v6 games.

Example

"Halo's matchmaking uses TrueSkill 2 under the hood — that's why new accounts have huge rating swings." The high uncertainty causes large updates.

Related terms

• Elo
• Glicko-2
• MMR
• matchmaking