Playing position influences the relative age effect in senior rugby union

Abstract

Objectives. – Many elite sporting populations contain an over-representation of individuals born early in the year and an under-representation of players born late in the year; this phenomenon is known as the relative age effect (RAE). There has been limited examination of the RAE in rugby union. Specifically, the present study sought to extend previous research by exploring whether playing position influenced the existence of the RAE in rugby union. Equipment and methods. – The birth dates and playing position of 1122 professional and 869 amateur senior French rugby union players registered during the 2014/15 season were obtained from an on-line statistics database. Birth dates were transformed into quartiles (Q) which corresponded to the selection year (Q1, Jan-Mar), and the distribution of player births compared with the distribution of births in the general French population across the period in question. Results. – Chi-square Goodness of Fit tests revealed an RAE at both professional and amateur levels, characterised by an under-representation of players born in the last quarter of the year. Furthermore, results indicated that an RAE existed for forwards but not backline players. Back row forwards in particular showed a pronounced RAE. Conclusion. – The existence of the RAE within senior French rugby union is influenced by player position, but not by playing level. These findings should guide coaches and talent development officers when reviewing their youth development programmes.