  One of the main goals of online competitive games is increasing player
engagement by ensuring fair matches. These games use rating systems for
creating balanced match-ups. Rating systems leverage statistical estimation to
rate players' skills and use skill ratings to predict rank before matching
players. Skill ratings of individual players can be aggregated to compute the
skill level of a team. While research often aims to improve the accuracy of
skill estimation and fairness of match-ups, less attention has been given to
how the skill level of a team is calculated from the skill level of its
members. In this paper, we propose two new aggregation methods and compare them
with a standard approach extensively used in the research literature. We
present an exhaustive analysis of the impact of these methods on the predictive
performance of rating systems. We perform our experiments using three popular
rating systems, Elo, Glicko, and TrueSkill, on three real-world datasets
including over 100,000 battle royale and head-to-head matches. Our evaluations
show the superiority of the MAX method over the other two methods in the
majority of the tested cases, implying that the overall performance of a team
is best determined by the performance of its most skilled member. The results
of this study highlight the necessity of devising more elaborated methods for
calculating a team's performance -- methods covering different aspects of
players' behavior such as skills, strategy, or goals.
