Steingröver Christina, Wattie Nick, Baker Joseph, Helsen Werner F, Schorer Jörg
Department of Sport and Motion, Institute of Sport Science, University of Oldenburg Oldenburg, Germany.
Faculty of Health Sciences, University of Ontario Institute of Technology, Oshawa ON, Canada.
Front Psychol. 2017 Mar 7;8:278. doi: 10.3389/fpsyg.2017.00278. eCollection 2017.
Selection biases based on the use of cut-off dates and the timing of athletes' birthdates have been termed relative age effects. These effects have been shown to differentially affect individuals involved in sport. For example, young male soccer players born early in their age group are overrepresented in elite teams while studies in adult soccer indicated potential carry-over effects from talent development systems. This two-study approach focuses on the processes within multi-year age groups in youth and adult elite soccer and on the role of players' age position within the age band with regard to players' birth year and birth month. Study 1 tests for an interaction of two different types of relative age effects among data from participants in the last five Under-17 FIFA World Cups (2007-2015). Analyses revealed a significant global within-year effect and varying birthdate distributions were found between confederations. Even stronger effects were found for constituent year effects. For the total sample, a multi-way frequency analysis (MFA) revealed an interaction with a pattern of a stronger within-year effect for the younger year group. This study highlights the need to consider interactions between different types of age effects. The main aim of Study 2 was to test for carry-over effects from previously found constituent year effects among players participating in the 2014 soccer World Cup and, therefore, to test for long-term effects of age grouping structures used during earlier stages of talent development. A secondary purpose of this study was to replicate findings on the existence of within-year effects and to test whether effects vary between continental confederations. No significant interaction between constituent year and within-year effects was shown by the MFA among the World Cup sample and previous findings on varying within-year effects were replicated. Results indicate that long-term effects of age grouping structures in earlier high-level talent development structures exist.
基于截止日期的使用和运动员出生日期的时间所产生的选择偏差被称为相对年龄效应。这些效应已被证明会对参与体育运动的个体产生不同影响。例如，在精英球队中，同一年龄组中出生较早的年轻男性足球运动员占比过高，而对成年足球运动员的研究表明，人才培养体系可能存在延续效应。这两项研究聚焦于青年和成年精英足球运动员多年龄组内的过程，以及球员在年龄区间内的年龄位置（考虑球员出生年份和月份）所起的作用。研究1在最近五届国际足联17岁以下世界杯（2007 - 2015年）参与者的数据中，测试两种不同类型相对年龄效应的相互作用。分析揭示了显著的全年整体效应，并且各联合会之间的出生日期分布有所不同。对于组成年份效应，发现了更强的影响。对于总样本，多向频率分析（MFA）揭示了一种相互作用，即较年轻年份组的全年效应更强。这项研究强调了考虑不同类型年龄效应之间相互作用的必要性。研究2的主要目的是测试在参加2014年足球世界杯的球员中，先前发现的组成年份效应的延续效应，从而测试在人才培养早期阶段所采用的年龄分组结构的长期影响。本研究的第二个目的是重复关于全年效应存在的研究结果，并测试这些效应在各大陆联合会之间是否存在差异。多向频率分析（MFA）在世界杯样本中未显示组成年份效应和全年效应之间存在显著相互作用，并且重复了先前关于全年效应不同的研究结果。结果表明，早期高水平人才培养结构中的年龄分组结构存在长期影响。
