# Relative age effects and player pathways in international ice hockey: a longitudinal multi-cohort analysis

## TL;DR

This study examines how birth date affects career paths in ice hockey across four countries, showing early-born players have advantages but late-born players catch up later.

## Contribution

The study provides a longitudinal, multi-cohort analysis of relative age effects in international ice hockey across four nations.

## Key findings

- Relative age effects are present in all four hockey nations, with early-born players overrepresented in early career stages.
- Late-born players begin to emerge during the transition to junior level (U20).
- Nation-specific differences in the impact of relative age effects were observed.

## Abstract

Past research shows that relative age effects (RAEs) are highly prevalent in ice hockey. Early-born players benefit from more exposure, especially in the early stages of development, and are frequently considered “more talented.” Although RAEs are apparent in these early stages, little is known about how it affects pathways leading to the highest levels of competition. This study aims to look more closely at the associations between RAEs and players’ career trajectories in 4 hockey nations: Canada, Finland, Czechia, and Slovakia. Specifically, it aims to: (1) evaluate the prevalence of RAEs in each country, (2) identify players’ career pathways and examine the impact of RAEs on the players, and (3) compare these effects for each nation.

Data were drawn from 4,306 players (100% males born between 1992 and 2002), who were invited to national development and selection camps between 2009 and 2019. Trajectory clusters were estimated from the players’ participation in 8 career milestones, from U17 to representation of their country at the Olympic Games. Group comparisons were conducted based on birth quartiles and hockey nations.

The results confirmed the presence of RAEs in the four hockey nations. Consistent with past research, early-born players are overrepresented in the early career stage, whereas late-born players begin to emerge during transition to junior level (U20). Some nation-specific differences were observed.

This provides further support for the stakeholders of ice hockey association looking to enhance their national team selection processes and discover structuring pathways that offer development opportunities for all groups of players.