Expert opinion on classification for footballers with vision impairment: Towards evidence-based minimum impairment criteria.

In Para sport, the aim of classification is to minimize the impact of impairment on the outcome of competition. Despite requirements of the International Paralympic Committee Athlete Classification Code for classification to be evidence-based and sport-specific, sports for athletes with VI, including football, use the same generic classes across almost all sports. The aim of this study was to consult with experts to establish the needs and challenges for developing a code-compliant system of classification for VI football. A panel of 18 experts with international experience in VI football (16.8 ± 10.2 years) took part in a three-round Delphi study using online surveys. Results showed that the panel did not think that the current system completely fulfils the aim of classification. The panel identified measures of visual function they considered to be relevant but are not currently measured during classification including dynamic acuity, depth and motion perception, and contrast and light sensitivity. Moreover, they identified technical skills such as ball control, dribbling and passing, as well as perceptual-cognitive skills, as most likely to be affected by vision impairment. Findings outline the need for change and offer a framework for future research to develop an evidence-based classification for VI football.

Is impaired coordination related to match physical load in footballers with cerebral palsy of different sport classes?

Impaired coordination is a characteristic feature in cerebral palsy (CP) football players. This study aimed to determine the relationships of three coordination tests with match physical load during competition of para-footballers from different sport classes. Records from 259 para-footballers from 25 national teams were obtained in four international competitions held in 2018 and 2019. The three coordination tests were conducted prior to competition (i.e., rapid heel-toe, side-stepping, and split jumps), and physical match load was recorded by GPS devices during the real game: i.e., maximum/mean, total distance, distance covered at different speed zones, number of accelerations/decelerations at different intensities, and player load. FT1 and FT3 players have the lowest and highest performance in all the coordination tests, respectively, but inconclusive between-groups differences were obtained (p=0.022‒0.238). Split jumps and side-stepping tests are associated with the performance of moderate and high accelerations during competition (r = -0.20‒0.71; p<0.01). Significant correlations (r = 0.36‒0.71; p<0.01) were obtained between all the coordination measures. Coordination tests better discriminate those with more severe impairments and some evidence for the validity of the new CP football sport classes is provided. Further research is necessary to identify the portion of the variance in sports performance that coordination explains.

Coding Body Language in Sports: The Nonverbal Behavior Coding System for Soccer Penalties.

Nonverbal behavior (NVB) plays an important role in sports. However, it has been difficult to measure, as no coding schemes exist to objectively measure NVB in sports. Therefore, the authors adapted the Body Action and Posture Coding System to the context of soccer penalties, validated it, and initially used this system (Nonverbal Behavior Coding System for Soccer Penalties [NBCSP]) to explore NVB in penalties. Study 1 demonstrated that the NBCSP had good to excellent intercoder reliability regarding the occurrence and temporal precision of NVBs. It also showed that the coding system could differentiate certain postures and behaviors as a function of emotional valence (i.e., positive vs. negative emotional states). Study 2 identified differences in NVB for successful and missed shots in a sample of penalties (time spent looking toward the goal, toward the ground, right arm movement, and how upright the body posture was). The authors discuss the utility of the coding system for different sport contexts.

Talent identification and development in soccer since the millennium.

At the turn of the millennium, a review paper was published in this journal on talent identification and development in soccer (Williams & Reilly, 2000). In the current paper, we assess progress made in this field over the last twenty years relative to the areas for future research highlighted in the original review. We evaluate developments in light of the calls made by Williams and Reilly to: a) undertake more multidisciplinary rather than mono-disciplinary research; b) embrace longitudinal rather than cross-sectional research designs; c) expand the research base on female football; and, d) better identify the subjective criteria used by scouts when selecting one player over another for entry into a formalised training environment. The body of mono-disciplinary research on this topic continues to expand, and progress has been made in publishing multidisciplinary, prospective, longitudinal data sets, along with advanced statistical modelling procedures, as well as in identifying the experiential criteria used by scouts. We found some variables in these studies have predictive value from adolescence to adult performance level in soccer. We present suggestions for future research to enhance knowledge and understanding of the best practices underpinning the identification and development of future generations of professional players.

A bioecological perspective on talent identification in junior-elite soccer: A Pan-European perspective.

Elite soccer clubs across Europe spend ever-increasing sums of money on transfers and salaries for world-class players. Consequently, clubs' talent identification and development processes for junior players have become more professionalised. Based on a holistic ecological approach, this study presents an analysis of talent identification practices across some of the most productive soccer academies in Europe (N = 11). Data were collected via semi-structured interviews with 11 heads of academy recruitment from clubs in the "big five" European leagues. Clubs were purposively sampled based on their player productivity ranking. Interviews ranged from 52:26 minutes to 114:06 minutes in length (m = 87:53 ± 20.10 minutes). This study argues that holistic ecological approaches the environments were characterised through the interplay of factors that ranged from high-level internal to international level relationships. This resulted in the identification and recruitment of players from local and international environments. The purpose of recruitment was suggested to have a dual purpose: recruitment of players for the first team; recruitment of players for further development/monitoring and/or selling to another club.

Evaluation of soccer players under the Moneyball concept.

The recruitment of athletes with limited resources is a global problem in professional sports. In US Major League Baseball, the experience of the Oakland Athletics' general manager in the last decade turned his "Moneyball" model into a synonym of quantitative analysis in the transfer market of baseball players. His strategy focused on hiring players with outstanding technical skills but relatively low market value. This study adapted this model to the framework of a multiple criteria decision aid (MCDA), by selecting undervalued players who have complementary abilities. The novelty here refers to the joint use of four algorithms explored by the composition of probabilistic preferences (CPP) (i.e., ranking, classification, dynamic evaluation and regularity analysis) and their application to soccer player performance evaluation. The new model analysed the recent transfer of a left-back soccer player to Europe. The results indicated 12 opportunities for better investment, among 32 left and right-back players considered. Two years later, the value of the same player was considerably lower. He played only five matches in the 2018-2019 season, without scoring or providing any assists. On the other hand, the players better classified by the CPP-MB model presented higher performances and market values.

A Fraction of Recommended Practices: Implementation of the FIFA 11+ in NCAA Soccer Programs.

Background and Objectives: National Collegiate Athletic Association (NCAA) soccer coaches implement numerous warm-up and flexibility strategies to prepare athletes for training and competition. The Fédération Internationale de Football Association (FIFA) developed the 11+ injury prevention program to reduce non-contact injuries. This study aimed to analyze the level of familiarity with and implementation of the evidence-based FIFA 11+ amongst NCAA Division I (DI) and Division III (DIII) men's and women's soccer coaches. Materials and Methods: NCAA soccer coaches in the United States received an Institutional Review Board-approved survey hyperlink. A total of 240 coaches completed the survey. The respondents represented 47.5% men's and 52.5% women's teams distributed within DI and DIII programs. Descriptive statistics are reported as frequency counts and mean ± standard deviation where applicable. Pearson's chi-square tests were performed to assess potential differences with a significance level set at α < 0.05. Results: The results indicated that approximately 62% of the respondents reported being familiar with the FIFA 11+ program. Of those coaches familiar with the program, 15.0% reported full implementation, 57.5% reported partial implementation, and 27.5% reported no implementation. Chi-square analyses revealed significant differences in FIFA 11+ implementation based upon division level (χ2 = 4.56, p = 0.033) and coaching certification levels (χ2 = 13.11, p = 0.011). Conclusions: This study indicates that there is a gap between FIFA 11+ knowledge and actual implementation. To reduce the risk of non-contact injury, there is a need to educate coaches and athletic trainers on the purpose of the FIFA 11+ program and how to perform the exercises correctly.

Classification of playing position in elite junior Australian football using technical skill indicators.

​In team sport, classifying playing position based on a players' expressed skill sets can provide a guide to talent identification by enabling the recognition of performance attributes relative to playing position. Here, elite junior Australian football players were a priori classified into 1 of 4 common playing positions; forward, midfield, defence, and ruck. Three analysis approaches were used to assess the extent to which 12 in-game skill performance indicators could classify playing position. These were a linear discriminant analysis (LDA), random forest, and a PART decision list. The LDA produced classification accuracy of 56.8%, with class errors ranging from 19.6% (midfielders) to 75.0% (ruck). The random forest model performed at a slightly worse level (51.62%), with class errors ranging from 27.8% (midfielders) to 100% (ruck). The decision list revealed 6 rules capable of classifying playing position at accuracy of 70.1%, with class errors ranging from 14.4% (midfielders) to 100% (ruck). Although the PART decision list produced the greatest relative classification accuracy, the technical skill indicators reported were generally unable to accurately classify players according to their position using the 3 analysis approaches. This player homogeneity may complicate recruitment by constraining talent recruiter's ability to objectively recognise distinctive positional attributes.

Premier League academy soccer players' experiences of competing in a tournament bio-banded for biological maturation.

Individual differences in the growth and maturation have been shown to impact player performance and development in youth soccer. This study investigated Premier League academy players' experiences of participating in a tournament bio-banded for biological maturation. Players (N = 66) from four professional soccer clubs aged 11 and 14 years and between 85-90% of adult stature participated in a tournament. Players competed in three 11 vs 11 games on a full size pitch with 25-min halves. Sixteen players participated in four 15-min focus groups and were asked to describe their experiences of participating in the bio-banded tournament in comparison to age group competition. All players described their experience as positive and recommended the Premier League integrate bio-banding into the existing games programme. In comparison to age-group competitions, early maturing players described the bio-banded games more physically challenging, and found that they had to adapt their style of play placing a greater emphasis on technique and tactics. Late maturing players considered the games to be less physically challenging, yet appreciated the having more opportunity to use, develop and demonstrate their technical, physical, and psychological competencies. Bio-banding strategies appear to contribute positively towards the holistic development of young soccer players.

Longitudinal development of match-running performance in elite male youth soccer players.

This study longitudinally examined age-related changes in the match-running performance of retained and released elite youth soccer players aged 8-18 years. The effect of playing position on age-related changes was also considered. Across three seasons, 263 elite youth soccer players were assessed in 1-29 competitive matches (988 player-matches). For each player-match, total distance and distances covered at age group-specific speed zones (low-speed, high-speed, sprinting) were calculated using 1 Hz or 5 Hz GPS. Mixed modeling predicted that match-running performance developed nonlinearly, with age-related changes best described with quadratic age terms. Modeling predicted that playing position significantly modified age-related changes (P < 0.05) and retained players covered significantly more low-speed distance compared with released players (P < 0.05), by 75 ± 71 m/h (mean ± 95% CI; effect size ± 95% CI: 0.35 ± 0.34). Model intercepts randomly varied, indicating differences between players in match-running performance unexplained by age, playing position or status. These findings may assist experts in developing training programs specific to the match play demands of players of different ages and playing positions. Although retained players covered more low-speed distance than released players, further study of the actions comprising low-speed distance during match play is warranted to better understand factors differentiating retained and released players.

Validation of digit-length ratio (2D:4D) assessments on the basis of DXA-derived hand scans.

BACKGROUND: The second-to-fourth digit-length ratio (2D:4D) may be a correlate of prenatal sex steroids, and it has been linked to sporting prowess. The aim of the study was to validate dual-energy X-ray-absorptiometry (DXA) as a technique to assess 2D:4D in soccer players under 15 years of age (U-15). METHODS: Paired X-ray and DXA scans of the left hands of 63 male U-15 elite soccer players (age: 14.0 ± 0.3 years) were performed, and 2D:4D was then compared between the two techniques. The 2D:4D measurements were performed twice by two blinded raters. Intrarater and interrater reliability, as well as agreement between the X-ray and the DXA assessments, were tested. RESULTS: Intrarater reliabilities of both raters using X-ray with intraclass correlation coefficients (ICCs) of 0.97 and 0.90 were excellent. Using DXA, the ICCs were 0.90 and 0.91 thus also showing excellent reliability. Interrater reliabilities were excellent using both the X-ray (ICC of 0.94) and the DXA (ICC of 0.90), assessments respectively. Bland-Altman plots demonstrated that the 2D:4D ratios of the two raters did not differ significantly between the X-ray and the DXA assessments. The standard errors of estimate were 0.01 for both techniques. The 95% limits of agreement of ±0.018 (±2.0%) and ±0.023 (±2.6%), respectively, were within the acceptable tolerance of 5%, and showed very good agreement. CONCLUSION: DXA offered a replicable technique for assessing 2D:4D in youth soccer players. Therefore, the DXA technique seems to be an alternative method for evaluating 2D:4D in youth sports.

The Contribution of Youth Sport Football to Weekend Physical Activity for Males Aged 9 to 16 Years: Variability Related to Age and Playing Position.

The aims of this study were (1) to determine minutes of moderate-to-vigorous physical activity (PA) and vigorous PA accrued in youth sport football (also internationally referred to as soccer), and the contribution toward daily weekend moderate-to-vigorous PA and vigorous PA for males aged 9-16 years, and (2) to investigate variability in these outcomes related to age and playing position. One hundred and nine male grassroots footballers (Mean age = 11.98 ± 1.75 years) wore a GT3× accelerometer for 7 days. Weekend youth sport football participation and playing position were recorded. Youth sport football moderate-to-vigorous PA (M = 51.51 ± 17.99) and vigorous PA (M = 27.78 ± 14.55) contributed 60.27% and 70.68% toward daily weekend moderate-to-vigorous PA and vigorous PA, respectively. Overall, 36.70% of participants accumulated ≥60 min moderate-to-vigorous PA and 69.70% accrued ≥ 20 min of vigorous PA during youth sport. For participants aged 13 to16 years, youth sport football moderate-to-vigorous PA and vigorous PA were significantly higher, and contributed a greater amount toward daily weekend moderate-to-vigorous PA and vigorous PA than for participants aged 9-12 years (p = <.01). Youth sport football is an important source of moderate-to-vigorous PA and vigorous PA at the weekend for male youth, and particularly for adolescents. Participation may offer opportunity for weekend engagement in vigorous PA toward health enhancing levels.

Effect of team rank and player classification on activity profiles of elite wheelchair rugby players.

The aim of the current study was to establish which indicators of mobility are associated with successful wheelchair rugby performance and determine whether these indicators differed across classification. Data were collected from 11 international teams during 30 matches (353 match observations) using a radio-frequency-based, indoor tracking system across two tournaments. Players (n = 111) were first grouped by team rank as determined by their International Wheelchair Rugby Federation (IWRF) world ranking (LOW, MID, HIGH) and then into one of four groups based on their IWRF classification: Group I (0.5), Group II (1.0-1.5), Group III (2.0-2.5) and Group IV (3.0-3.5). The volume of activity (relative distance and mean speed), peak speed and time spent within classification-specific arbitrary speed zones were calculated for each individual. Although no differences were identified in the volume of activity, playing time was significantly reduced in LOW (34:51 ± 8:35) compared to MID (48:54 ± 0:51) and HIGH (45:38 ± 9:53), which was further supported by the greater number of substitutions performed by LOW. HIGH achieved greater peak speeds (3.55 ± 0.40 m · s-(1)) than LOW (3.27 ± 0.42 m · s(-1)) and MID (3.45 ± 0.41 m · s(-1)). Peak speed was further shown to be classification-dependent (P ≤ 0.005), whereby HIGH Groups III and IV players achieved greater peak speeds than LOW and MID. The time spent performing high-intensity activities was also greater in HIGH compared to LOW and MID, whilst further influenced by classification (P ≤ 0.0005). To conclude, peak speed and the ability to perform a greater number of high-intensity activities were associated with successful performance in wheelchair rugby.

Anthropometric and Somatotype Characteristics of Young Soccer Players: Differences Among Categories, Subcategories, and Playing Position.

Considering that anthropometric parameters are important factors in the performance of the soccer players, the aim of this study was to explore the differences in anthropometric and somatotype characteristics of Italian young soccer players. Weight, height, body mass index, and somatotype of 112 young soccer players, grouped in Giovanissimi "A" (14 years), "B" (13 years), and "C" (12 years) as well as Allievi "B" (15 years) and "A" (16 years) and "Juniores" (older than 17 years), were evaluated. Statistical analysis tests were computed at p ≤ 0.05, and an analysis of variance for each somatotype was calculated to analyze the main effects and interactions of the factors: categories, subcategories, and playing position. Bonferroni's post hoc analysis was used to identify differences among mean values. Considering all subjects, we have found significant differences in categories, subcategories, and playing position between anthropometric values and a somatotype value of 2.8-3.8-2.9. Significant differences have found among goalkeepers and the others playing position in endomorphy (p ≤ 0.001) and with defenders and midfielders in ectomorphy (p < 0.01) components, whereas no differences in mesomorphy. Analyzing the interaction between subcategories and playing position factors, a significant effect was found only in the endomorphy component (p = 0.05). The analysis of anthropometric characteristic of Italian young soccer players indicates that players have high muscularity value and low adiposity. This study showed the presence of somatotype differences for playing position within categories also in the youngest categories and subcategories, in particular, in the endomorphy component. Young soccer players should be trained with more appropriate and specific training load to avoid the increased injury risk during adolescence.

Lower-extremity strength ratios of professional soccer players according to field position.

Previous investigators have proposed that knee strength, hamstrings to quadriceps, and side-to-side asymmetries may vary according to soccer field positions. However, different results have been found in these variables, and a generalization of this topic could lead to data misinterpretation by coaches and soccer clubs. Thus, the aim of this study was to measure knee strength and asymmetry in soccer players across different field positions. One hundred and two male professional soccer players performed maximal concentric and eccentric isokinetic knee actions on the preferred and nonpreferred legs at a velocity of 60° · s. Players were divided into their field positions for analysis: goalkeepers, side backs, central backs, central defender midfielders, central attacking midfielders, and forwards. Results demonstrated that only goalkeepers (GK) differed from most other field positions on players' characteristics, and concentric peak torque across muscles. Although all players presented functional ratios of the preferred (0.79 ± 0.14) and nonpreferred (0.75 ± 0.13) legs below accepted normative values, there were no differences between positions for conventional or functional strength ratios or side-to-side asymmetry. The same comparisons were made only between field players, without inclusion of the GK, and no differences were found between positions. Therefore, the hamstrings to quadriceps and side-to-side asymmetries found here may reflect knee strength functional balance required for soccer skills performance and game demands across field positions. These results also suggest that isokinetic strength profiles should be considered differently in GK compared with other field positions due to their specific physiological and training characteristics.

Characterization of the Sprint and Repeated-Sprint Sequences Performed by Professional Futsal Players, According to Playing Position, During Official Matches.

The purposes of this study were to investigate sprints and to characterize repeated-sprint sequences (RS) performed by athletes during professional futsal matches. We analyzed 97 players during 5 official matches using the DVideo automatic tracking system. The sprints were analyzed during the first and second halves according to playing position, and RS were categorized according to the number of sprints and the time between them. The results showed an increase (F[1, 2520] = 3.96; P = .046) in the sprint duration from the first (mean = 3.1 ± 1.3) to the second half (mean = 3.2 ± 1.2). However, no differences were found for other variables (distance covered, peak velocity, initial velocity, recovery time between sprints, and sprints performed per minute) or among playing positions. In addition, when considering RS, the results showed that RS comprising two sprints interspersed with a maximum of 15 seconds of recovery were significantly more frequent than other RS. The findings of this study characterizing the sprinting features of futsal players can help coaches to plan physical training and assessments according to the requirements of the sport.

Effect of the Modification of the Number of Players, the Size of the Goal, and the Size of the Field in Competition on the Play Actions in U-12 Male Football.

A player's sports development involves a long process. The modification of rules for youth players seeks to adapt the sport to the child and his/her development. The manipulation of rules affects the technical and tactical skills demonstrated by players and, therefore, their development. The objective of this study was to analyse the effect of a reduction in the number of players (from 8 per team to 5 per team), the size of the goal (from 6 × 2 m to 3 × 2 m) and the playing space (from 58 × 38 m to 38 × 20 m), on the technical and tactical actions in youth football players. A quasi-experimental A-B-A design was implemented to assess the effect of the rule changes. The players (n = 40) played three tournaments using two competition formats (official rules, modified rules, and official rules). The results show that the use of the modified rules generated a greater number and variability in the technical-tactical actions, a greater number of actions with teammates in the pass line, a greater continuity in the game, a greater number of attack and defence actions in areas close to the goal, and favours team play. The experimental format fits the players' individual progression better (U-12) as well as the players' and teams' collective development, and it will allow players to evolve from the individual development of previous stages.

[Anthropometric differences per playing position in Chilean professional footballers]. / Diferencias antropométricas por posición de juego en futbolistas profesionales chilenos.

INTRODUCTION: Introduction: given the characteristics of soccer, the tendency in the selection of these athletes and their allocation in certain game positions has been conditioned by the morphological characteristics that they present, so that the knowledge of anthropometric particularities by playing position is a relevant antecedent for the technical bodies of professional football. The objective of the present investigation is to identify and compare the anthropometric characteristics by playing position of Chilean professional soccer players. Methods: a total of 390 professional male soccer players, from 15 Chilean professional clubs, were evaluated morphologically by means of the measurement of 25 anthropometric variables, with which the body composition, the somatotype and the Z-score of Phantom were estimated. A Chi-square test with significance level of p < 0.05 was used to compare the variables between groups using SPSS software others players (greater adipose and muscular mass). As for a sample of active subjects, soccer players have a significantly different body composition, similarly occurs when compared to Phantom, where height, weight and muscle mass are greater and fat mass is lower. Conclusion: professional footballers differ by game position compared to other non-sports players and Phantom.

INTRODUCCIÓN: Introducción: dadas las características del fútbol, la tendencia en la selección de estos deportistas y su asignación en determinadas posiciones de juego se han visto condicionadas por las características morfológicas que estos presenten, por lo que el conocimiento de las particularidades antropométricas por posición de juego es un antecedente relevante para los cuerpos técnicos del fútbol de élite. El objetivo de la presente investigación es identificar y comparar las características antropométricas por posición de juego de jugadores de fútbol profesional chileno. Métodos: un total de 390 futbolistas profesionales varones, pertenecientes a 15 clubes profesionales chilenos, fueron evaluados morfológicamente mediante la medición de 25 variables antropométricas, con las que se estimaron la composición corporal, el somatótipo y los Z-score de Phantom. Para la comparación de las variables entre los grupos se utilizó una prueba Chi-cuadrado con nivel de significancia de p < 0,05, utilizando el software SPSS versión 21. Resultados: se observan diferencias entre las posiciones de juego, especialmente entre los porteros y el resto de los jugadores (p < 0,001), quienes presentan más de 2 kg de masa muscular y más de 1,8 kg de masa adiposa, frente a las otras posiciones de juego. Respecto de una muestra se sujetos activos, los futbolistas presentan una composición corporal significativamente distinta; de igual manera ocurre al comparar con Phantom, donde la estatura, el peso y la masa muscular son mayores y la masa adiposa es menor. Conclusión: los futbolistas profesionales presentan diferencias por posición de juego y en comparación a otros sujetos no deportistas y a Phantom.

A Coding System to Quantify Powerful Actions in Soccer Match Play: A Pilot Study.

PURPOSE: The powerful activity profile of elite soccer match play has not been documented appropriately to inform specific maximal power assessment and development criteria. The aims of the current study were to develop a reliable  soccer-specific powerful action (SSPA) notational analysis coding system that could be used to compare frequency and durations of powerful actions during elite youth soccer match play. METHODS: Sixteen elite male English Premier League (EPL) Academy players (19 ± 1 yrs) were recorded by an individual camera during 16 competitive EPL U18 and U21 games. Video footage was analyzed using performance analysis software and SSPAs were coded according to the following categories: initial acceleration, leading acceleration, sprint, unilateral jump and bilateral jump. RESULTS: The SSPA coding system demonstrated very good inter- and intra-rater reliability (kappa coefficients ≥ 0.827). Elite youth EPL soccer players undertook significantly more initial (31 ± 9) and leading (37 ± 12) accelerations than sprints (8 ± 3; p = .014, d = 1.7, and p < .001, d = 1.7, respectively) and jumps (6 ± 5; p = .002, d = 1.7 and p < .001, d = 1.7, respectively). Players performed a significantly greater number of initial and leading accelerations with action durations below 1.5 s compared to above 1.5 s (p = .001, d = 1.6, and p = .002, d = 1.4), respectively. CONCLUSIONS: Our SSPA coding system provides a reliable observational instrument for quantifying the frequency and duration of powerful actions performed during elite soccer match play. In our sample of elite youth soccer players, horizontal accelerations of short duration (< 1.5 s) from different starting speeds appear the most dominant powerful action in elite youth soccer match play.

Relative age effects in professional German soccer: a historical analysis.

Relative age effects (RAEs) refer to the specific selection, participation and attainment (dis)advantages which occur as a result of physical and cognitive differences within annual age-grouped cohorts. The present study tracked the existence of RAEs in professional German soccer by examining RAEs in players, head coaches and referees who represented professional soccer clubs or officiated in the Bundesliga from 1963/64 to 2006/07. An additional objective was to consider the social-cultural mechanisms responsible for RAEs, so for a similar period, population and soccer participation information was also obtained. When players were categorised into half decade groups, chi-square analyses predominantly showed RAEs across the history of the Bundesliga, irrespective of dates used for annual age grouping in junior/youth soccer. RAEs were also apparent for head coaches but not for referees. Participation data indicated consistent and progressive growth from 1950 to 1990. RAEs influence the likelihood of attaining professional player and coaching status in German soccer. With many coaches being former players, inequalities associated with annual age-grouping appear to extend beyond a playing career. Officiating was not affected, with referees suggested to emerge from an alternative development pathway. Increased popularity of soccer may have propagated RAEs over time, through intensification of competition and selection mechanisms.