Relative age effects in international rugby union: Consequences of changing the cutoff date and exploring youth to senior transitions

ABSTRACT

Relative age effects (RAEs) are independent of specific cutoff dates that can vary from country to country. However, the consequences of changing the selection cutoff dates within a national sport organization are unknown. Further, the transition from international youth to senior representation is yet to be explored in rugby union. Thus, the aims of this article were twofold: Study 1 compared the birth quarter (BQ) distributions of the England Rugby Football Union (RFU) under-18 representatives based on September to August and January to December selection cutoff dates. Study 2 explored the BQ distributions within the RFU international development pathway through analyzing the under-18, under-20, and senior representatives, as well as the BQ distributions of youth players who were subsequently capped at senior level. Chi-square analysis was used to compare BQ distributions in each sample against expected distributions. Results revealed a corresponding shift of a skewed birthdate distribution favoring chronologically older players that was mediated by specific cutoff dates (p < 0.05). Moreover, whilst RAEs were present within both youth cohorts (p < 0.05), it was not apparent at the senior level (p > 0.05). Furthermore, during the transition from international youth to senior representation, more chronologically older players were successfully capped.

KEYWORDS:

• Talent identification
• talent development
• athlete development
• reversal effect
• age grade rugby
• rugby football union

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes

1. Selection for both the September to August and January to December fixtures were generally carried out with a weighting toward the September to August fixtures being made of up players who were perceived to be stronger compared to those in the January to December fixtures. This was due to the September to August fixtures being selected from players across one whole English academic year. Although this policy is a generalization, it is important to consider that this did factor into the selection process.

2. A fixture is defined as a competitive match that has taken place between two nations.

3. The year 2008 was when the RFU started recording this data; therefore, this dataset includes all the information that was available during analysis.

4. The year 2008 was when the RFU started recording this data; therefore, this dataset includes all the information that was available during analysis.

5. It is important to note that recent data from the RFU shows how 77% of the 2019 Rugby World Cup squad represented England at under-18 level, whilst 81% represented England at under-20 level. In addition, there may have been senior international players who were eligible for under-18 and under-20 selection but not included due to data being captured from 2008–2019.