Expertise has been extensively studied in several sports over recent years. The specificities of how excellence is achieved in Association Football, a sport practiced worldwide, are being repeatedly investigated by many researchers through a variety of approaches and scientific disciplines. The aim of this review was to identify and synthesise the most significant literature addressing talent identification and development in football. We identified the most frequently researched topics and characterised their methodologies. A systematic review of Web of Science™ Core Collection and Scopus databases was performed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines. The following keywords were used: “football” and “soccer”. Each word was associated with the terms “talent”, “expert*”, “elite”, “elite athlete”, “identification”, “career transition” or “career progression”. The selection was for the original articles in English containing relevant data about talent development/identification on male footballers. The search returned 2944 records. After screening against set criteria, a total of 70 manuscripts were fully reviewed. The quality of the evidence reviewed was generally excellent. The most common topics of analysis were (1) task constraints: (a) specificity and volume of practice; (2) performers’ constraints: (a) psychological factors; (b) technical and tactical skills; (c) anthropometric and physiological factors; (3) environmental constraints: (a) relative age effect; (b) socio-cultural influences; and (4) multidimensional analysis. Results indicate that the most successful players present technical, tactical, anthropometric, physiological and psychological advantages that change non-linearly with age, maturational status and playing positions. These findings should be carefully considered by those involved in the identification and development of football players. This review highlights the need for coaches and scouts to consider the players’ technical and tactical skills combined with their anthropometric and physiological characteristics scaled to age. Moreover, research addressing the psychological and environmental aspects that influence talent identification and development in football is currently lacking. The limitations detected in the reviewed studies suggest that future research should include the best performers and adopt a longitudinal and multidimensional perspective.

Talent Identification and Development in Male Football: A Systematic Review

The relative age effect (RAE) and its relationships with maturation, anthropometry, and physical performance characteristics were examined across a representative sample of English youth soccer development programmes. Birth dates of 1,212 players, chronologically age-grouped (i.e., U9's-U18's), representing 17 professional clubs (i.e., playing in Leagues 1 & 2) were obtained and categorised into relative age quartiles from the start of the selection year (Q1 = Sep-Nov; Q2 = Dec-Feb; Q3 = Mar-May; Q4 = Jun-Aug). Players were measured for somatic maturation and performed a battery of physical tests to determine aerobic fitness (Multi-Stage Fitness Test [MSFT]), Maximal Vertical Jump (MVJ), sprint (10 & 20m), and agility (T-Test) performance capabilities. Odds ratio's (OR) revealed Q1 players were 5.3 times (95% confidence intervals [CI]: 4.08-6.83) more likely to be selected than Q4's, with a particularly strong RAE bias observed in U9 (OR: 5.56) and U13-U16 squads (OR: 5.45-6.13). Multivariate statistical models identified few between quartile differences in anthropometric and fitness characteristics, and confirmed chronological age-group and estimated age at peak height velocity (APHV) as covariates. Assessment of practical significance using magnitude-based inferences demonstrated body size advantages in relatively older players (Q1 vs. Q4) that were very-likely small (Effect Size [ES]: 0.53-0.57), and likely to very-likely moderate (ES: 0.62-0.72) in U12 and U14 squads, respectively. Relatively older U12-U14 players also demonstrated small advantages in 10m (ES: 0.31-0.45) and 20m sprint performance (ES: 0.36-0.46). The data identify a strong RAE bias at the entry-point to English soccer developmental programmes. RAE was also stronger circa-PHV, and relatively older players demonstrated anaerobic performance advantages during the pubescent period. Talent selectors should consider motor function and maturation status assessments to avoid premature and unwarranted drop-out of soccer players within youth development programmes.

https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0137238&type=printable

Soccer Player Characteristics in English Lower-League Development Programmes: The Relationships between Relative Age, Maturation, Anthropometry and Physical Fitness.

The presence of the relative age effect (RAE) has been widely reported; however, its underlying causes have not yet been determined. With this in mind, the present study examined if anthropometry and performance were different amongst older and younger soccer players born in the same year. Eighty-eight young soccer players participated in the study (age 9.75 ± 0.30). Anthropometric measurements, physical tests (sprint, agility, endurance test, jump and hand dynamometry) and the estimation of the maturity status were carried out. Most players (65.9%) were born in the first half of the year. Older players were taller (P < 0.05), had longer legs (P < 0.01) and a larger fat-free mass (P < 0.05). Maturity offset was smaller in the older boys (P < 0.05); however, age at peak height velocity was similar. Older boys performed better in velocity and agility (P < 0.05) and particularly in the overall score of performance (P < 0.01). Stepwise regression analysis revealed that chronological age was the most i...

Relationship between the relative age effect and anthropometry, maturity and performance in young soccer players.

Introduction: Selection of younger athletes for advanced training in elite sport is assumed to be based on identification of innate talent. Previous researchers have identified relative age effects to influence these selection processes; however, maturation status and skeletal age effects, which have the potential to be a greater influence, have not been widely examined.Methods: Skeletal age (categorising athletes as: early maturing, on time, or late maturing via wrist and hand X-ray and Fels classification) and birth quarter are documented for 472 boys from Elite Youth football academies and compared to reference normative data to assess their effect on academy selection.Results: It is seen that maturation status has a much stronger influence – approximately 10-fold – on selection with a systematic over-representation of early maturing athletes in elite football academies, an effect that increases with age.Conclusions: Our results demonstrate that athletes are being chosen in large by their matur...

Skeletal maturation status is more strongly associated with academy selection than birth quarter

Relative Age Effect (RAE) is the breakdown by both age grouping and dates of birth of athletes. In the past 20 years the existence of this effect has been shown with higher or smaller impact in multiple sports, including soccer. The purpose of this study was to identify the existence of RAE in European soccer players. The sample included 841 elite soccer players who were participants in the UEFA European Soccer Championship in different categories. The professional category (n = 368), U-19 (n = 144) and U-17 (n = 145) were in 2012, and U-21 was in 2011 (n = 184). The Kolmogorov-Smirnov test and the Levene test recommended the use of nonparametric statistics. The results obtained by the square test ( the Kruskal-Wallis test and Cohen's effect sizes revealed the existence of RAE (χ(2) = 17.829, p < 0.001; d = 0.30), with the size of their different effects depending on their category or qualifying round achieved by the national team and the existence of significance in the observed differences by category. Therefore, we could continue examining RAE which is present in elite soccer, and could be considered a factor that influences performance of the national teams tested. RAE was not evident in the professional teams analysed, however it was present in the three lower categories analysed (youth categories), with its influence being greater on younger age categories (U-17).

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Relative Age Effect in UEFA Championship Soccer Players

The aim of the study was to determine whether there is empirical evidence for advantages in performance of soccer teams because of their relative age. The practice of selecting youth players according to their momentary performance leads to relative age effects, which in turn lead to inefficient talent selection. We used the median of the birth dates as a measure of the effect size of the relative age effect and the Kolmogorov-Smirnov test to assess its significance. For the 2008–2009 season, birth dates in the three German U-17 first leagues for soccer were examined (911 players). More than half of the 41 teams differed significantly from the distribution of the corresponding German cohort. There was a significant correlation between the relative age effect and success defined by teams' final rankings (Spearman's ρ = 0.328, P = 0.036). Regression analyses revealed that with a median of birth dates one month earlier the team is expected to finish 1.035 ranks better. Accordingly, selecting early b...

/pdf/the-relative-age-effect-and-success-in-german-elite-u-17-1m80vkb5ck.pdf

The relative age effect and success in German elite U-17 soccer teams

Optimal control in the critical phase of movement: A functional approach to motor planning processes

The intention of the present study was to examine, if interruptions are used as a tactical means in international competitions and if law changes influence the duration. Therefore, the 32 matches o...

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Game stoppages as a tactical means in soccer – a comparison of the FIFA World Cups™ 2006 and 2014

There is empirical evidence that children's physical activity is dependent on climatic conditions. In addition, a correlation between physical activity level and physical fitness has been identified. In this longitudinal study, we investigate whether seasons have an influence on physical fitness. A total of 145 German elementary school children were tested every six months over a two-year period. We used the German Motor Test 6-18 to assess physical fitness. Performance in the 6-min endurance run (P < 0.001), bidirectional jumping (P < 0.001), the standing long jump (P = 0.026), the 20 m sprint (P = 0.006) and the stand-and-reach task (P = 0.017) was significantly better in summer than in winter. There were no differences in the ability to balance backwards (P = 0.120); in the winter, the results for push-ups (P < 0.001) and sit-ups (P < 0.001) were better than those in the summer. We have shown that physical fitness is significantly influenced by the season. Consequently, when children's fitness tests are used (e.g. as the basis for intervention programs, for classifying health-risk groups or for recognising talent), the season in which testing occurred should be reported and accounted for in future studies.

/pdf/seasonal-variations-in-physical-fitness-among-elementary-5nekqs3sul.pdf

Seasonal variations in physical fitness among elementary school children

The secular trend of reduced physical fitness (PF) leads to increased health risks. The aim of the present paper is to analyse various current factors that affect health behaviour with respect to the course of PF over 2 years. A path analysis combined with a latent growth curve analysis was based on a study that was conducted between June 2008 and June 2010 with 145 primary German school children (52.1% male, average age at baseline 7.95 years ± 0.95). PF was tested with the German Motor Test 6–18. For the mean PF and the course of PF, direct and indirect influences were shown over three levels, including migration background on the first level and physical activity (PA) on the second level. Body mass index (BMI) impacted the mean PF but not the course of PF. The influence of sedentary behaviour on the mean PF was diminished (compared to bivariate analysis) due to its common variance mainly with BMI. PA affected not only current PF in children but also the course of PF (aintercept = .28, P = .001;...

/pdf/does-current-behaviour-predict-the-course-of-children-s-1z0bj3ay5b.pdf

Claudia Augste

Papers

The relative age effect and success in German elite U-17 soccer teams

Optimal control in the critical phase of movement: A functional approach to motor planning processes

Game stoppages as a tactical means in soccer – a comparison of the FIFA World Cups™ 2006 and 2014

Seasonal variations in physical fitness among elementary school children

Does current behaviour predict the course of children's physical fitness?