Relative age effects (RAEs) are a well-known phenomenon within youth sports. Although research consistently shows participation biases across the youth sporting domain, there appears to be a paucity of research focusing on interventions aimed at mitigating RAEs. This chapter aims to address this challenge by proposing a new grouping strategy to reduce RAEs. First, in contrast to the traditional approach using chi-squared goodness-of-fit test to determine RAEs, the average team age (ATA) and relative age effect index (RAEi) are introduced. These measurable variables are used to study the underlying mechanisms causing the relative age bias in youth football in the Netherlands. Results show that teams with an average age closer to the beginning of the cut-off date are more likely to win (e.g., 1.51 points per game for older teams vs. 1.32 points per game for younger teams). As such, a competitive advantage appears to increase the average age of teams within the selection year (e.g., a predetermined age group that is eligible to in a certain competition), creating an over-representation of relatively older players. Therefore, an alternative grouping strategy is proposed, whereby eligibility is based on the average age of a team rather than the individual age of the athlete competing inside the selection year. This ATA grouping approach operates by setting the average age of the team to create opportunities for both younger and older players to be selected and, potentially, for the reduction of RAEs. Since this grouping policy is yet to be empirically evaluated in practice, this chapter concludes with recommendations for future research to examine the ATA approach.