Faculty of Physical Activity and Sports Sciences, Institute of Biomedicine (IBIOMED), University of León - Universidad de León, León, Spain.
Independent Researcher, Spain.
J Sports Sci Med. 2023 Dec 1;22(4):700-706. doi: 10.52082/jssm.2023.700. eCollection 2023 Dec.
The age difference among individuals of the same group is known as Relative Age. Relative Age Effect refers to the consequences derived from it, such as delayed physical, cognitive and mental development of children born later in the year. The aim of this study was to observe the Relative Age Effect by analyzing players' dates of birth throughout three seasons in the two professional football competitions in Spain based on the game positions and the teams' classification at the end of the season. The sample was made up of players (n=4097) from both professional competitions (n=1864), and (n=2233). The data were collected from two public-access football statistics websites. The cut-off date was established on January 1, the year was divided into four quartiles (Q1: January-March, Q2: April-June, Q3: July-September and Q4: October-December). Results confirmed significant differences on dates of births' distribution (p<0.05) for the competitions - and - during three seasons, as well as for player position, with a larger effect observed for goalkeepers and defenders. Significant difference was also observed depending on classification. Results show a clear decreasing percentage of those born in quartile 4 in relation to those born in quartile 1, it can be concluded that the Relative Age Effect phenomenon is present in the Spanish professional football which may lead to an inappropriate talent selection technique in football, with recruitment oriented to the short term, to immediate results, and possibly caused by the early start of the player selection process.
个体之间的年龄差异被称为相对年龄。相对年龄效应是指由此产生的后果，例如出生较晚的儿童在身体、认知和心理方面的发展延迟。本研究旨在通过分析西班牙两个职业足球比赛中三个赛季球员的出生日期，观察相对年龄效应，依据是球员在比赛中的位置和赛季结束时球队的排名。样本由来自两个职业比赛的球员组成(n=4097)，其中(n=1864)和(n=2233)。数据来自两个公共足球统计网站。截止日期设定在每年的 1 月 1 日，一年分为四个季度(Q1：1 月至 3 月，Q2：4 月至 6 月，Q3：7 月至 9 月，Q4：10 月至 12 月)。结果证实了三个赛季中两个比赛（- 和 -）的出生日期分布有显著差异（p<0.05），以及球员位置有显著差异，守门员和后卫的影响较大。根据排名也观察到了显著差异。结果表明，与出生在第一季度的人相比，出生在第四季度的人明显减少，这表明相对年龄效应现象存在于西班牙职业足球中，这可能导致足球选拔技术不当，招聘倾向于短期、即时结果，可能是由于球员选拔过程的早期开始。
