Relative Age Effect (RAE) among elite and young soccer players

What is it about?

This is a Systematic Review in English published in Sports (MDPI). This is a brief and "friendly" outline of the article. Please, find all the references in the document "Soccer and Relative Age Effect: a walk among Elite Players and Young Players" (2017) 1.- Background 1.1.- Definition of Relative Age Effect (RAE) In sports players are grouped by their chronological age in order to ensure equal opportunities. However, the physical and cognitive development are different in people who born in the first part of the year in contrast to people who born in the final part of the year. In this regard, an over-representation of players born during the first two quarters of the year (and consequently, an under-representation of players born during the last two quarters of the same year) is observed in the majority of teams around the world. 1.2.- Where is RAE? RAE is significantly observed during the adolescence years (due to the physical and cognitive advantages). However, RAE seems to decrease after the adolescent period (due to the maturation is less determinant). In this sense, young players who were born in January will have a whole year of maturation advantage compared to children born in December. RAE is observed in several sports where physical attributes are very important (e.g., soccer, basketball or handball) around the world. However, it is also observed an "inverse effect" in non-physical sports activities such as shooting sports or golf. 1.3.- Factors which influence the degree of RAE Extrinsic factors (such as socioeconomic determinants) and intrinsic factors (such as the physical and physiological characteristics). 1.4.- The pioneers who research this phenomenon The first study about RAE and sport was carried out by Barnsley and Thompson (1985) in the United States. They observed that the youngest players (who born in the final part of the year) were more frustrated due to their participation in competition events were less. The first study about RAE and soccer was conducted by Barnsley, Thompson and Legault (1992). They also observed that the players born in the first month of the year were over-represented, while those born in the last months of the same year were under-represented. 2.- The research 2.1.- Aim of the present investigation The aim of this study is to analyze the presence of RAE in young soccer players (from 6 to 18 years old) and in elite soccer players (more than 18 years old). The main hypothesis is formulated as a significant increase of RAE on competitive soccer players from 2010 to 2016 around the world. 2.2.- Questions (I) Is RAE maintained across age categories? (II) Is RAE present in female soccer players? (III) Is RAE influenced by the players position on the pitch? (IV) Is RAE related to physical advantages of the older players in contrast to the young players born in the same year? (V) Is RAE increasing during 2010 to 2016 around the world? (V) Is there any solution which helps to reduce RAE? 2.3.- Research selection - Databases: SPORTDiscus, Medline, EBSCO-host and Google Scholar - Keywords (Please, see Figure 1): 'Relative Age Effect', 'Soccer', 'Football', 'Elite players', 'Young players' - English Boolean data type: 'And', 'Not', 'Or' - Selection criteria: (1) Articles published in English or Spanish, (2) published from 2010 to 2016, (3) which included information about the RAE among young and elite soccer players; (4) the information about the RAE related to maturation, anthropometric characteristics, and physical finess; (5) and information about RAE in several representaive countries. 2.3.- Results Please, see Table 1 (summary of the investigation related to the RAE). 2.4.- Discussion This systematic review confirms the presence of RAE among lower soccer age categories and elite soccer categories around the world. Please, see Figure 2 (summary of the topics affected by RAE and its impacts) to understand that RAE is influenced by the coaches, who look for results in competition. In this sense, it is observed biased distribution at female and male soccer players around the world. However, RAE also depends on the size of the country: if it is a small countries RAE is not significantly observed due to the "open door policies" in contrast to big countries. 3.- Practical applications How we can reduce RAE? A) To alter or rotate the annual cut-off date, which normally is on 31 December, in order to offer different groups of players with a relative age advantage. This could balance the system season. B) To create alternative ways of grouping children for competition based on anthropocentric attributes in order to reduce the maturation effect. C) To develop internal changes in soccer academies as well as improving some rules in the competition. D) To educate coaches and inform parents that the genuine potential of a soccer player comes at the end of the maturation process. E) To improve the selection test which guarantees a real evaluation of technical and tactical aspects, as well as enhancing the playing time of all players, which increases the motivation. F) To develop corrective adjustments between datasets could help to improve the validity of the player's assessment and selection process. G) To design smaller competition groups at young categories, as well as group categorized players according to the level of ability which ensures greater opportunity of participation and increases motivation. 4.- Conclusion RAE is confirmed. This phenomenon is increasing during the last years in youth elite competition. However, no significant RAE was found in elite soccer teams due to the fact that physical advantages do not exist in older players. Even though recommendations to avoid RAE is proposed, more investigations are needed in order ot carry out an effective tool which might reduce RAE.

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Photo by Viktor Talashuk on Unsplash

Photo by Viktor Talashuk on Unsplash

Why is it important?

The main results are discussed in several parts: - RAE among age categories - RAE in female soccer players - RAE on the pitch - Physical Advantages and RAE - RAE around the world. RAE during history. This investigation highlighted that RAE should be minimized. Several strategies should be to consider avoiding RAE in soccer or any other sport (please, see Figure 3: brief recommendation to avoid RAE in soccer)

Perspectives