Relationship Between the Relative Age Effect and Lengths of Professional Careers in Male Japanese Baseball Players: a Retrospective Analysis

Hiroki Nakata

doi:10.1186/s40798-017-0090-3

Abstract

BackgroundThe mechanisms underlying the relative age effect in sport events have been investigated for more than two decades. The present study focused on the relationship between the relative age effect and lengths of professional careers among professional male Japanese baseball players.MethodsThe birth dates of players and lengths of professional careers were collected from an official publication, and data were divided into four quarters (Q1: April–June; Q2: July–September; Q3: October–December; Q4: January–March of the following year) grouped by 3 years. Based on the data for Q4, the expected numbers for the lengths of professional careers were calculated for Q1, Q2, and Q3.ResultsThe number of players with professional careers of more than 19 years was significantly smaller in Q4 than in Q1, Q2, and Q3.ConclusionsThe relative age effect among professional male Japanese baseball players was associated with the lengths of professional careers. Relative age appears to be a very important factor for the development of expertise among male Japanese baseball players and involves long-term disadvantages after becoming professional players.

Highlights

The mechanisms underlying the relative age effect in sport events have been investigated for more than two decades
The relative age effect among professional male Japanese baseball players was associated with the lengths of professional careers
The present results indicate that a significant relative age effect exists in many junior sports and in the lengths of professional careers after becoming a professional player

Summary

Introduction

The mechanisms underlying the relative age effect in sport events have been investigated for more than two decades. The relative age effect is regarded as a contributing factor to sporting success. Relatively older children within a particular age group are more likely to achieve sporting success. This phenomenon has been called the relative age effect. Relatively older children (athletes) have a greater opportunity to participate in competitions and, may enhance their psychological, technical, and tactical abilities, thereby supporting greater athletic development [2]. The relative age effect has been confirmed in many types of sports, including baseball [3, 4], soccer [5,6,7,8], tennis [9], cricket [10], basketball [4, 11], NASCAR [12], sumo wrestling [4], rugby [13], judo [2], ice hockey [14,15,16,17], and winter sports [18,19,20,21]

Methods

Results

Discussion

Conclusion