The background of the article is the recurrent discussion about allocation of playing time in team sports involving children and young athletes. The objective is to analyse "why" playing time is a topic for discussion among parents, coaches and athletes. The following question is addressed: Under which condition is it "fair" to use "equal" and under which condition "fair" to use "unequal" playing time? Methodologically the article combines literature in the field of psychology, physiology and sociology--and simple mathematics is applied in developing a model for estimating playing time, frequency and timing of substitutions. The article shows that team sports are arenas where social interaction takes place, where norms and rules are internalized and where allocation of a given playing time implies inclusion and exclusion of individuals. The article shows that there exists a single, objective "unfair" allocation of playing time, but a variety of "fair." Lack of objective criteria drives the discussion of fair allocation of playing time. A policy implication of the findings is that an insight into psychosocial mechanisms can change practice to obtain a better and sustainable organization of team sports where young athletes are involved.