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Heilmann F, Kuhlig A, Stoll O. Relative age effects in German youth A and B men's soccer teams: survival of the fittest? Front Sports Act Living 2024; 6:1432605. [PMID: 39055171 PMCID: PMC11269141 DOI: 10.3389/fspor.2024.1432605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2024] [Accepted: 06/26/2024] [Indexed: 07/27/2024] Open
Abstract
The study investigates relative age effects (RAE) in German youth soccer (Youth Bundesliga A: January 2004 to December 2005 and B: January 2006 to December 2007; highest league in German youth soccer) and its persistence in third-division players. Data from the 2022-2023 season (120 teams, 3,174 players) were analyzed using chi-square tests. Significant RAE was found in the A-series (p < .001), B-series (p < .001), and third-division professionals (p < .001). Notably, RAE was prominent among younger players but less evident in older third-division players (p = .116), indicating a diminishing selection effect with age and professional tenure. Coaches and talent managers are advised to consider RAE and additional factors like player maturity in talent selection for more efficient talent management strategies, especially in youth academies.
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Affiliation(s)
- Florian Heilmann
- Movement Science Lab, Institute for Sport Science, Martin-Luther University Halle-Wittenberg, Halle (Saale), Germany
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2
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Ribeiro E, Barreira J, Carraco D, Galatti L, Götze M, Cal Abad CC. The relative age effect in under-17, under-20, and adult elite female soccer players. SCI MED FOOTBALL 2024; 8:153-160. [PMID: 36592346 DOI: 10.1080/24733938.2022.2164608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/29/2022] [Indexed: 01/03/2023]
Abstract
To investigate the RAE in elite female soccer players, the absolute and relative birthdate distributions of players who disputed the Women's World Cup were assessed. Differences between observed and expected distributions were analyzed using chi-square and effect sizes. The birthdates of 1224 female soccer players were assessed in Under-17 (N = 336), Under-20 (N = 336) and adult (N = 552) categories. There was no significant RAE in adult category for different playing positions and players in general (including all playing positions per age category). There was significant RAE for midfielders and players in general with mainly small effect sizes for the U-17 and U-20. In both age categories, players born in Q1 were over-represented with the highest quartile ratio for midfielders. In regard of RAE and success defined by final ranking at the World Cup, we found no significant differences between the birthdate distributions of players who participated in either the group stages or finally the knockout phases. Coaches should consider this information to avoid bias in talent programs designed to promote and select female soccer players independently of their birthdates. Young female players should be encouraged to learn to play in different field positions before to reach high-level performance.
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Affiliation(s)
- Elaine Ribeiro
- Department of Sport, Paulistano Athletic Club (CAP), São Paulo, Brazil
- Department of Post Gratuation, Singularidades Institute (iS), São Paulo, Brazil
| | - Júlia Barreira
- School of Applied Sciences, University of Campinas (UNICAMP), Limeira, Brazil
| | - Dayse Carraco
- Department of Post Gratuation, Singularidades Institute (iS), São Paulo, Brazil
| | - Larissa Galatti
- School of Applied Sciences, University of Campinas (UNICAMP), Limeira, Brazil
| | - Martin Götze
- Faculty of Sport Science, Institute of Movement and Training Science, University of Leipzig, Leipzig, Germany
| | - Cesar Cavinato Cal Abad
- Research Center of Sport Science, Social Service of Industry (SESI), São Paulo, Brazil
- Department of Physical Education, Lusófona Faculty of São Paulo (FLSP), Cotia, Brazil
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3
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Aku Y, Yang C. The relative age effect and its influence on athletic performance in Chinese junior female' tennis players. PLoS One 2024; 19:e0298975. [PMID: 38451907 PMCID: PMC10919619 DOI: 10.1371/journal.pone.0298975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 02/01/2024] [Indexed: 03/09/2024] Open
Abstract
The relative age effect (RAE) has been the focus of numerous studies; however, there are still fewer studies in women's sports than in men's sports. In this study, all female players (N = 2,255) who participated in Chinese junior tennis competitions (U12, U14, U16, and the National Junior Team) from 2014 to 2019 were investigated in terms of competitors' birth dates and year-end rankings. For the purposes of the analysis, the birth dates were also separated into quarters and half years. The study's objectives were to analyze the prevalence of the RAE among young Chinese female tennis players and to further examine how the RAE affects athletic performance. Differences between the observed and expected distributions of birth dates were tested using the chi-square statistic, and subsequent calculations were tested using odds ratios. The RAE was discovered to be present in every group of Chinese junior female tennis players (p < 0.001), with the proportions of those born in the first half of the year being 56.4% (U12), 53.1% (U14), and 57.0% (U16), respectively. The RAE for athletes selected for the National Women's Junior Tennis Team was even more significant, with the percentage of birth dates in the first half of the year at 61.2%. Finally, we observed a tendency for the effect of the RAE on the athletic performance of adolescent female tennis players to diminish with age.
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Affiliation(s)
- Yisheng Aku
- Department of Athletic Training, Chengdu Sport University, Chengdu, China
| | - Chengbo Yang
- Department of Athletic Training, Chengdu Sport University, Chengdu, China
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4
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Yagüe JM, Salguero A, Villegas A, Sánchez-Molina J, Molinero O. The Relative Age Effect in the Two Professional Men's Football Leagues in Spain. J Sports Sci Med 2023; 22:700-706. [PMID: 38045751 PMCID: PMC10690514 DOI: 10.52082/jssm.2023.700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 10/26/2023] [Indexed: 12/05/2023]
Abstract
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 (nLaLiga Santander=1864), and (nLaLiga Smartbank=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 - LaLiga Santander and LaLiga Smartbank - 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.
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Affiliation(s)
- José M Yagüe
- Faculty of Physical Activity and Sports Sciences, Institute of Biomedicine (IBIOMED), University of León - Universidad de León, León, Spain
| | - Alfonso Salguero
- Faculty of Physical Activity and Sports Sciences, Institute of Biomedicine (IBIOMED), University of León - Universidad de León, León, Spain
| | | | | | - Olga Molinero
- Faculty of Physical Activity and Sports Sciences, Institute of Biomedicine (IBIOMED), University of León - Universidad de León, León, Spain
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Bezuglov E, Malyakin G, Emanov A, Malyshev G, Shoshorina M, Savin E, Lazarev A, Morgans R. Are Late-Born Young Soccer Players Less Mature Than Their Early-Born Peers, Although No Differences in Physical and Technical Performance Are Evident? Sports (Basel) 2023; 11:179. [PMID: 37755856 PMCID: PMC10536659 DOI: 10.3390/sports11090179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Revised: 09/01/2023] [Accepted: 09/06/2023] [Indexed: 09/28/2023] Open
Abstract
The aim of the study was to compare the status of somatic maturity, anthropometry, strength, speed, and soccer-specific technical skills of players from leading youth soccer academies born in different quarters of the same calendar year. A total of 678 young male soccer players from eight leading Russian soccer academies took part in the study. The following anthropometric measures and physical characteristics were measured: height, weight, body mass index, countermovement jumps (CMJ), 5, 10, and 20 m sprints, speed dribbling, foot and body ball juggling, and short and long pass accuracy. The determination of somatic maturity as a percentage of projected adult height was collected. All subject dates of birth were divided into four quartiles according to the month of birth. The analysis of all data obtained was conducted both within the total sample and by quartiles of birth, according to the age group categories of 12-13 years, 14-15 years, and 16-17 years and the degree of somatic maturity. There was a widespread relative age effect, with 43.5% of early-born players and only 9.6% of late-born players representing the sample. Early-born players were more mature than late-born players (p < 0.001 and p < 0.001) but had no statistically significant differences in strength, speed, or soccer-specific skills.
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Affiliation(s)
- Eduard Bezuglov
- Department of Sports Medicine and Medical Rehabilitation, Sechenov First Moscow State Medical University, 119991 Moscow, Russia; (E.B.); (M.S.)
- High Performance Sports Laboratory, Sechenov First Moscow State Medical University, 119991 Moscow, Russia
| | - Georgiy Malyakin
- Department of Sports Medicine and Medical Rehabilitation, Sechenov First Moscow State Medical University, 119991 Moscow, Russia; (E.B.); (M.S.)
- High Performance Sports Laboratory, Sechenov First Moscow State Medical University, 119991 Moscow, Russia
| | - Anton Emanov
- High Performance Sports Laboratory, Sechenov First Moscow State Medical University, 119991 Moscow, Russia
| | - Grigory Malyshev
- High Performance Sports Laboratory, Sechenov First Moscow State Medical University, 119991 Moscow, Russia
| | - Maria Shoshorina
- Department of Sports Medicine and Medical Rehabilitation, Sechenov First Moscow State Medical University, 119991 Moscow, Russia; (E.B.); (M.S.)
| | - Evgeny Savin
- High Performance Sports Laboratory, Sechenov First Moscow State Medical University, 119991 Moscow, Russia
| | - Artemii Lazarev
- Department of Internal Medicine, Mount Sinai Hospital, Chicago, IL 60608, USA;
| | - Ryland Morgans
- Department of Sports Medicine and Medical Rehabilitation, Sechenov First Moscow State Medical University, 119991 Moscow, Russia; (E.B.); (M.S.)
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Brustio PR, Modena R, Boccia G, Vogliazzo M, Kelly AL. Youth-to-senior transition in women's and girls' football: Towards a better understanding of relative age effects and gender-specific considerations. PLoS One 2023; 18:e0283781. [PMID: 37141307 PMCID: PMC10159103 DOI: 10.1371/journal.pone.0283781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 03/16/2023] [Indexed: 05/06/2023] Open
Abstract
This study aimed to evaluate youth-to-senior transition and the relative age effect in Italian female football national teams. Birthdate data of 774 female players selected for Under 17 (N = 416), 19 (N = 265) and National Senior team (N = 93) were analysed. The youth-to-senior transition rate was determined by the number of youth players competing in the Senior National team (and vice versa), whilst birth quarter (Q) distributions with a chi-square goodness-of-fit test. Only 17.4% of youth players were able to be selected for the Senior National team, whereas 31.2% of the players reached the high-senior level without being selected for youth age groups. Data revealed a skewed birth date distribution in Under 17 and 19 teams (on average, Q1 = 35.6% vs Q4 = 18.5%) but not in the Senior National team. Youth players born in Q1 were two times more likely to be selected than in Q4. In Under 17, goalkeepers, defenders, and midfielders of Q1 players were overrepresented. However, Q4 players recorded higher conversion rates than Q1 (Q1 = 16.4% vs. Q4 = 25.0%). National youth experience may not be a prerequisite for being selected at the senior level. Moreover, this confers a higher probability of playing in the National Senior team than players not selected in youth rosters.
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Affiliation(s)
- Paolo Riccardo Brustio
- Department of Clinical and Biological Sciences, University of Turin, Turin, Italy
- NeuroMuscularFunction Research Group, School of Exercise & Sport Sciences, SUISM University, Turin, Italy
| | - Roberto Modena
- Faculty of Health Sciences and Social Care, Molde University College, Molde, Norway
- CeRiSM (Sport Mountain and Health Research Centre), University of Verona, Verona, Italy
| | - Gennaro Boccia
- Department of Clinical and Biological Sciences, University of Turin, Turin, Italy
- NeuroMuscularFunction Research Group, School of Exercise & Sport Sciences, SUISM University, Turin, Italy
| | - Matteo Vogliazzo
- School of Exercise & Sport Sciences (SUISM), University of Turin, Turin, Italy
| | - Adam Leigh Kelly
- Centre for Life and Sport Sciences (CLaSS), Faculty of Health, Education, and Life Sciences, Birmingham City University, Birmingham, West Midlands, United Kingdom
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Matsuda S, Ishigaki H. Trends in Relative Age Effects of Top-Level Female Soccer Players: A Japanese Study. Percept Mot Skills 2023; 130:984-998. [PMID: 36921122 DOI: 10.1177/00315125231162745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
Abstract
We investigated recent trends in relative age effect (RAE) findings of top-level female soccer players in Japan, using data from the 2016 to 2020 seasons. We conducted two main analyses: (a) An examination of RAE for all registered players in the Japan Women's Soccer League (Nadeshiko League) from 2016 to 2020; and (b) an examination of RAE of newly registered players in the league from 2017 to 2020. In the first analysis, we found a significant difference between the number of players born in Q1 (April-June) versus Q4 (January-March), with the number of players born in Q1 greater and with the ratio between these groups ranging from 1.5 to 1.7. In the second analysis, we found a significant relationship between Q1 and Q4 for the 2017 season alone. However, the Q1/Q4 ratio ranged from 1.4 to 1.9, and the semester ratio of S1 (Q1 + Q2))/S2 (Q3 + Q4) ranged from 1.2 to 1.3, suggesting a birth month bias. Thus, there was a RAE in female soccer players playing recently in Japan's top-level leagues; and the size of the effect did not change significantly across recent seasons.
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Affiliation(s)
| | - Hiroaki Ishigaki
- Department of Education, 13143The University of Tokyo, Tokyo, Japan
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Bezuglov E, Morgans R, Butovskiy M, Emanov A, Shagiakhmetova L, Pirmakhanov B, Waśkiewicz Z, Lazarev A. The relative age effect is widespread among European adult professional soccer players but does not affect their market value. PLoS One 2023; 18:e0283390. [PMID: 36952464 PMCID: PMC10035832 DOI: 10.1371/journal.pone.0283390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 03/08/2023] [Indexed: 03/25/2023] Open
Abstract
BACKGROUND The relative age effect (RAE) is most prevalent in highly competitive youth soccer and persists to a lesser extent in senior soccer. However, it is known that soccer players born in the second half of the year are as successful at senior level, indicating that they are equally talented although under-represented at youth level due to bias during the selection process, in which the emphasis is on more pronounced physical qualities in a specific period of time. Examining the prevalence of the RAE among professional soccer players depending on the level of competition and playing position, as well as analyzing the relationship between the player's birth quarter and market value, are of scientific interest. METHODS The dates of birth, playing position, and market value of all adult male soccer players included in the final rosters of teams from the top-division of 54 European countries, listed on www.transfermarkt.com on August 15th, 2020, were analyzed (18,429 soccer players in total). All players were categorized into four groups according to the quarter of birth (Q) and playing position. All teams were further sub-divided in groups depending on the soccer clubs' level of representation in the UEFA Champions League. RESULTS Of 18,429 players, 30.9% were born in Q1, 25.7% in Q2, 23.8% in Q3 and 19.6% in Q4. The number of soccer players born in Q1 was lower in less competitive leagues. The number of players born in Q1 decreased as the level of competition decreased; the highest percentage of these players was observed in clubs that are among the top 50 ranked in UEFA or compete in the most prestigious European championships. The RAE was less pronounced in teams that participate in lower competitive championships. There was no significant difference in market value between players playing position and level of competition when born in different quarters. Although, the most expensive soccer players in the European championships were late-born forwards. Players of various groups differed in their market value. CONCLUSIONS The RAE is currently prevalent in all the most competitive senior soccer leagues and teams in Europe regardless of playing position. There are no significant differences in market value between players of the same playing position and level of competition when born in different quarters. The most expensive soccer players in the European championships are forwards born in Q4. These findings may indicate that the under-representation of "late-born" soccer players in youth, and then consequently in adult soccer, is not associated with lower talent, but with other factors, possibly based on physiological characteristics and socio-cultural factors. Further measures are needed to mitigate the discriminatory effects of selection bias based on the RAE.
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Affiliation(s)
- Eduard Bezuglov
- Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russian Federation
- High Performance Sports Laboratory, Moscow Witte University, Moscow, Russian Federation
- Academy of Talents, Moscow, Russian Federation
| | - Ryland Morgans
- Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russian Federation
| | | | - Anton Emanov
- Academy of Talents, Moscow, Russian Federation
- Smart Recovery Sports Medicine Clinic, Moscow, Russian Federation
| | | | - Bekzhan Pirmakhanov
- Faculty of Medicine and Health Care, Department of Epidemiology, Biostatistics and Evidence-Based Medicine, Al-Farabi Kazakh National University, Almaty, Kazakhstan
- FC Kairat, Almaty, Kazakhstan
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Ruscello B, Morganti G, Apollaro G, Saponara A, Esposito M, Marcelli L, Filetti C, Porta M, Grossi A, Pantanella L. Relative age effect in Italian soccer: a cultural issue in talent management? J Sports Med Phys Fitness 2023; 63:136-143. [PMID: 35437304 DOI: 10.23736/s0022-4707.22.13663-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
BACKGROUND Relative age effect (RAE) is a well-known phenomenon among those involved in youth sports, especially when the sport being investigated is widespread and involves early selection for participation in national and international competitions. METHODS The purpose of this study was to verify whether the Italian youth soccer ecosystem has adapted to this issue over the years, comparing players born in 1995 and in 2005 and been playing in Under 16 teams in the appropriate years. The sample included 13 professional Italian soccer teams. The number of players analysed was 260 (1995) and 344 boys (2005), respectively, making a total of 604 players enrolled in this study. RESULTS Relative age effects were detected by χ2 goodness of fit tests both in players born in 1995 (P<0.000;V=0.40) and in 2005 (P<0.0001;V=0.39). χ2 test of independence showed no significant difference between the two groups of players (P=0.986;V=0.02), confirming a substantial parity of the phenomenon over the two investigated birth years. CONCLUSIONS Ten years of research and dissemination of RAE did not change the selection policies adopted by coaches and/or scouts, who favor relatively older players during the selection processes. Therefore, RAE appears as the result of the Talent Identification and Development Structures, characterized by early selection and early specialization, and which consider performance as the pre-requisite for gaining access to the next developmental stages. Sport organizations should be aware of this issue and counteract accordingly, since it is important to mitigate the presence of RAE, as it causes inequality of opportunity.
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Affiliation(s)
- Bruno Ruscello
- School of Sports Sciences and Exercise, Faculty of Medicine and Surgery, Tor Vergata University, Rome, Italy - .,School of Sports and Exercise Sciences, San Raffaele University, Rome, Italy - .,Department of Industrial Engineering, Faculty of Engineering, Tor Vergata University, Rome, Italy - .,LUISS SportLab, LUISS University, Rome, Italy -
| | - Gabriele Morganti
- School of Sports Sciences and Exercise, Faculty of Medicine and Surgery, Tor Vergata University, Rome, Italy
| | - Gennaro Apollaro
- School of Sports Sciences and Exercise, Faculty of Medicine and Surgery, Tor Vergata University, Rome, Italy
| | - Antonio Saponara
- School of Sports Sciences and Exercise, Faculty of Medicine and Surgery, Tor Vergata University, Rome, Italy
| | - Mario Esposito
- School of Sports Sciences and Exercise, Faculty of Medicine and Surgery, Tor Vergata University, Rome, Italy
| | - Lorenzo Marcelli
- School of Sports Sciences and Exercise, Faculty of Medicine and Surgery, Tor Vergata University, Rome, Italy.,Department of Industrial Engineering, Faculty of Engineering, Tor Vergata University, Rome, Italy
| | | | - Marco Porta
- School of Sports and Exercise Sciences, San Raffaele University, Rome, Italy
| | - Alberto Grossi
- School of Sports Sciences and Exercise, Faculty of Medicine and Surgery, Tor Vergata University, Rome, Italy
| | - Laura Pantanella
- School of Sports Sciences and Exercise, Faculty of Medicine and Surgery, Tor Vergata University, Rome, Italy
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Andrew M, Finnegan L, Datson N, Dugdale JH. Men Are from Quartile One, Women Are from? Relative Age Effect in European Soccer and the Influence of Age, Success, and Playing Status. CHILDREN (BASEL, SWITZERLAND) 2022; 9:1747. [PMID: 36421196 PMCID: PMC9689054 DOI: 10.3390/children9111747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 09/21/2022] [Accepted: 11/10/2022] [Indexed: 11/16/2022]
Abstract
The relative age effect (RAE) is characterised by an overrepresentation of athletes born earlier in the selection year. Whilst an RAE is consistently evident in male soccer, examinations in female players remain limited. The aim of the present study was to examine the influence of sex, as well as age, success, and playing status in European soccer players. The sample consisted of a total of 6546 soccer players from 55 soccer nations that competed in recent European Championship qualification campaigns. Results indicated an evident RAE in male [p = 0.017] but not female [p = 0.765] players. Male players were over-represented by players born in the first quartile for the U17 [p < 0.001] and U19 [p = 0.001] levels, however, this over-representation did not transfer to senior levels. No RAE was observed at any level for female players. Inside each age group, a slight selection bias towards those born in the first quartile for successful squads was observed but did not significantly differentiate between qualification status for either male or female players. Results from this study highlight the disparity in RAE prevalence between male and female players and raise further questions regarding the value of selecting relatively older players to metrics of success, transition, and selection for senior international soccer.
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Affiliation(s)
- Matthew Andrew
- Department of Sport and Exercise Sciences, Institute of Sport, Manchester Metropolitan University, Manchester M15 6BH, UK
| | - Laura Finnegan
- Football Research Group, Department of Sport and Exercise Science, South East Technological University, X91 HE36 Munster, Ireland
| | - Naomi Datson
- Institute of Sport, Nursing and Allied Health, University of Chichester, Chichester PO19 6PE, UK
| | - James H. Dugdale
- School of Applied Sciences, Edinburgh Napier University, Edinburgh EH14 1DJ, UK
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11
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Maturation Selection Biases and Relative Age Effect in Italian Soccer Players of Different Levels. BIOLOGY 2022; 11:biology11111559. [PMID: 36358260 PMCID: PMC9687510 DOI: 10.3390/biology11111559] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 10/21/2022] [Accepted: 10/22/2022] [Indexed: 11/06/2022]
Abstract
Simple Summary Soccer academies and societies research young players who are supposed to possess great motor skills. In association with these, adolescents who appear to be talented exhibit more developed anthropometric and body composition features than untalented players. Although many selected soccer players appear to present an earlier maturation than their contemporaries, it is not clear whether soccer teams of different competition levels are aware of this aspect and considered these discrepancies in the scouting selection process. In addition, it remains unclear if the biological maturity and relative effect are two interchangeable methods of evaluation and if one of them deserves to be preferred by the soccer scouters. This research aims to investigate the effect of the team level, maturity status and relative-age effect, and their interactions, on body characteristics, cellularity, and physical performance in adolescent soccer players. Despite the relative age effect remaining the easier analysis to consider, the evaluation of maturity status seems to be the most reliable method to detect better capabilities due to early growth. Abstract Soccer is a sport practiced all over the world, in which players are expected to show specific physical and technical skills. Soccer academies look for young talented individuals to develop promising players. Although several parameters could affect the players’ performance, the relative age effect (RAE) and the maturity status appeared debated. Therefore, this study compared the differences in RAE and biological maturity among the players of two Italian soccer teams of different levels and to understand their interaction effects with the competition level on youth players’ physical characteristics and abilities. One hundred and sixty-two young soccer players from the U12 to U15 age categories of the elite (n = 98) and non-elite (n = 64) teams were recruited. The prevalence of maturity status and RAE was observed. Many anthropometric parameters, BIA vectors, and motor tests (CMJ, Sprint, RSA) were carried out. The maturity status had a greater effect on several anthropometric characteristics and on 15 m sprint, while it affected the CMJ only in U12 (F = 6.187, p ≤ 0.01). Differently, the RAE seemed to priorly affect the U13 and U15 categories in body composition, whereas its effect appeared on the 15-m sprint (F(3, 45) = 4.147, p ≤ 0.01) and the RSA (F(3, 45) = 3.179, p ≤ 0.05) in the U14 category. In addition, early matured players or those who were born in the first six months presented cellular characteristics similar to adult elite players. Soccer professionals should be encouraged to monitor the maturity status to better interpret changes in the physical performance of young soccer players to guide adequate training plans.
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12
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Low prevalence of relative age effects in Luxembourg’s male and female youth football. PLoS One 2022; 17:e0273019. [PMID: 35998177 PMCID: PMC9398004 DOI: 10.1371/journal.pone.0273019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 07/31/2022] [Indexed: 11/19/2022] Open
Abstract
The relative age effect (RAE) is a well-established phenomenon in football. However, while the majority of previous studies focussed on established football nations, it remains unclear if the constraint of a limited population of soccer players in smaller countries associated with less strict selection procedures may reduce the risk of RAE. This study aims to investigate the RAE in Luxembourg that follows an ‘open-door’ selection policy in youth football due to the limited pool of players. Birthdates from all licensed and actively playing Luxembourgish youth footballers including all players of the youth national teams (396 girls and 10981 boys) competing in the season 2018/2019 were analysed and categorised into birth quarters and semesters. To further investigate a performance dependence of the RAE in amateur leagues, success was determined based on the teams’ rankings at the end of the season. Differences between observed and expected birthdate distributions were calculated across all licensed players and age groups, within the national teams, and for the top- and bottom-tier football teams using chi-square statistics. While a RAE was absent across all age groups (except U7), significant RAEs with high effect sizes were observed in the top-level and national teams. These findings contrast the substantial RAE effects in large football nations and suggest that open selection systems might reflect an environmental constraint that limit the prevalence of RAE in football. Further, this study indicates that a performance dependence of the RAE is not limited to high level football but already occurs on an amateur level.
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Queeney JR, Kelly AL, McGourty P, Horgan P. The relative age effect in the Gaelic Athletic Association (GAA): A mixed methods approach. SCI MED FOOTBALL 2022:1-11. [PMID: 35787228 DOI: 10.1080/24733938.2022.2096918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
In the Gaelic Athletic Association (GAA), Talent Academies (TAs) and senior teams cater for high performing players, however only two previous studies have quantified the relative age effect (RAE; i.e., a selection bias favouring those born near the beginning of the cut-off date) in these cohorts. Additionally, no studies to date have explored stakeholder understanding of the RAE using qualitative methods. This study aimed to: (a) quantify the RAE in TAs and senior teams, and (b) investigate stakeholder perspectives of the talent development environment, providing practical insight into the RAE. A mixed methods sequential explanatory study design was employed. Phase one involved a retrospective analysis of longitudinal data for the frequency and distribution of births using TA (n=12,445) and senior (n=8,752) players. Phase two comprised two focus groups of key stakeholders [coaches (n=4) and Talent Development Leaders (n=4)] at TA and senior level. Analysis revealed a significant difference between TA birth quarter (BQ) distributions compared with expected distributions across all age groups (P<0.001; BQ1=30.4% vs. BQ4=17.6%), while at senior level, there were no significant differences between observed and expected BQ distributions (χ2 (df=3) =3.812, P=0.282). In phase two, inductive analysis revealed three higher order themes: (a) understanding of the RAE, (b) selection criteria, and (c) player characteristics. The GAA are encouraged to reflect on the practice of chronological age band grouping, investigate possible solutions to limit the effects of the RAE, and offer support programmes to educate key stakeholders on the potential impact of the RAE on talent development.
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Affiliation(s)
- Jamie R Queeney
- Gaelic Athletic Association, Croke Park, Jones' Rd, Drumcondra, Dublin 3, Ireland
| | - Adam L Kelly
- Centre for Life and Sport Sciences (CLaSS), Faculty of Health, Education and Life Sciences, Birmingham City University, Birmingham, West Midlands, United Kingdom
| | - Padraig McGourty
- Department of Health and Nutritional Sciences, Atlantic Technological University, Sligo, Ireland
| | - Peter Horgan
- Gaelic Athletic Association, Croke Park, Jones' Rd, Drumcondra, Dublin 3, Ireland
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de la Rubia A, Lorenzo A, Bjørndal CT, Kelly AL, García-Aliaga A, Lorenzo-Calvo J. The Relative Age Effect on Competition Performance of Spanish International Handball Players: A Longitudinal Study. Front Psychol 2021; 12:673434. [PMID: 34267706 PMCID: PMC8276001 DOI: 10.3389/fpsyg.2021.673434] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 05/31/2021] [Indexed: 12/03/2022] Open
Abstract
Background: Competitive success is the ultimate objective of elite professional sport organisations. Relative age effects (RAE) impact athlete selection processes in the short and long-term performance. The aims of this study were: (i) examine the presence of RAE by gender, competitive level, and playing position, as well as evaluate the impact of RAE on individual (goals, percentage of effectiveness in shots, saves; percentage of effectiveness in saves, assists, turnovers, steals, blocked shots, penalties, minutes played, and minutes played per match) and collective competition performance (final team position); and (ii) analyse the impact of RAE on the evolutionary trends of individual performance in international competitions throughout 16 seasons in Spanish handball (2005–2020). Methods: The sample included 631 Spanish handball players (male: n = 359; female: n = 272). A Chi-square goodness-of-fit test was used to assess whether a skewed birthdate distribution occurred. A one-way analysis of variance (ANOVA) of independent measures was used to examine the individual and collective statistical parameters by birth quartiles. A linear regression in a Hopkins sheet were performed to compare individual performance trends. Results: The results revealed RAE in the male formative categories (p < 0.001), as well as the male and female senior categories (p < 0.05). By position, RAE especially affected the “centre-back” in the male formative (p < 0.01) and senior categories (p < 0.05). No significant relationship between RAE and individual performance was found in male formative categories, while an impact of RAE on the “minutes played” was detected in the female senior category (p < 0.05). With regard to collective performance, a higher number of relatively older handball players was observed in the best ranked teams in the male formative categories and in the quarter-final teams in the female formative categories (p < 0.05). Among the male players, relatively older players spent more minutes on the court than relatively younger players, although this advantage dissipated over time and did not lead to better performance. Among the female players, relatively younger players were found to perform better as the level of competitive handball increased. Discussion: These findings are important for talent identification and development policies in sport federations and other elite sport institutions by demonstrating the many unintended consequences of selections to international competitions at the youth level.
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Affiliation(s)
- Alfonso de la Rubia
- Departamento de Deportes, Facultad de Ciencias de la Actividad Física y del Deporte-Instituto Nacional de Educación Física, Universidad Politécnica de Madrid, Madrid, Spain
| | - Alberto Lorenzo
- Departamento de Deportes, Facultad de Ciencias de la Actividad Física y del Deporte-Instituto Nacional de Educación Física, Universidad Politécnica de Madrid, Madrid, Spain
| | | | - Adam Leigh Kelly
- Department of Sport and Exercise, Research Centre for Life and Sport Sciences, Birmingham City University, Birmingham, United Kingdom
| | - Abraham García-Aliaga
- Departamento de Deportes, Facultad de Ciencias de la Actividad Física y del Deporte-Instituto Nacional de Educación Física, Universidad Politécnica de Madrid, Madrid, Spain
| | - Jorge Lorenzo-Calvo
- Departamento de Deportes, Facultad de Ciencias de la Actividad Física y del Deporte-Instituto Nacional de Educación Física, Universidad Politécnica de Madrid, Madrid, Spain
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Figueiredo P, Seabra A, Brito M, Galvão M, Brito J. Are Soccer and Futsal Affected by the Relative Age Effect? The Portuguese Football Association Case. Front Psychol 2021; 12:679476. [PMID: 34122274 PMCID: PMC8194498 DOI: 10.3389/fpsyg.2021.679476] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 04/26/2021] [Indexed: 11/18/2022] Open
Abstract
A better understanding of the relative age effect (RAE) in youth will increase the awareness of the need for reducing the bias of (de)selection. Thus, we investigated the RAE in youth female and male soccer and futsal players in Portugal, using nationwide data. Birthdates of 5,306 female and 126,285 male soccer players, and 2,437 female and 23,988 male futsal players (U7–U19), registered in Portugal during the season 2019–2020, and Portuguese National teams (from U15 to AA soccer teams and from U17 to AA futsal teams) were analyzed. Data were categorized into age groups and certification levels [no certification, basic football training center, football school, and training institution] of the respective clubs/academies. Birthdates were stratified from the start of the selection year using quartiles (Q) and semesters (S). Differences between the observed and expected birthdate distributions were analyzed using chi-square statistics, and RAEs were calculated using odds ratios (OR). In both soccer and futsal, female players, in the age category U9, RAEs were found (Q1 vs. Q4, OR: 1.49 and 1.84, respectively). In male soccer, differences in the birthdate distribution were observed in all age categories (U7–U19) with significant OR between all comparisons (Q and S). In contrast, an over-representation of young male futsal players (Q1 vs. Q4) was observed only in the age categories U7 and U9 (OR: 1.54 and 1.34, respectively). The stratification by certification level showed a significant RAE for all certification levels in male soccer players. In contrast, in male futsal players, the RAE was significant only in clubs and academies with the highest level. For National teams, the RAE was more pronounced in male soccer, particularly in the U16 and U17 (OR: 9.84 and 12.36, respectively). Data showed a RAE in female and male youth soccer and futsal, particularly in male, younger age categories, and in clubs and academies having a higher certification level, which could be accompanied by a loss of valuable elite players during the youth phase of their careers. Thus, adjustments in the systems and structure of talent identification are recommended to prevent RAE-related discrimination in youth soccer and futsal.
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Affiliation(s)
- Pedro Figueiredo
- Portugal Football School, Portuguese Football Federation (FPF), Oeiras, Portugal.,Research Center in Sports Sciences, Health Sciences and Human Development (CIDESD), University Institute of Maia (ISMAI), Maia, Portugal
| | - André Seabra
- Portugal Football School, Portuguese Football Federation (FPF), Oeiras, Portugal.,Research Centre in Physical Activity, Health and Leisure (CIAFEL), Faculty of Sport, University of Porto, Porto, Portugal
| | - Marta Brito
- Portugal Football School, Portuguese Football Federation (FPF), Oeiras, Portugal
| | - Marta Galvão
- Portugal Football School, Portuguese Football Federation (FPF), Oeiras, Portugal
| | - João Brito
- Portugal Football School, Portuguese Football Federation (FPF), Oeiras, Portugal
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Leyhr D, Bergmann F, Schreiner R, Mann D, Dugandzic D, Höner O. Relative Age-Related Biases in Objective and Subjective Assessments of Performance in Talented Youth Soccer Players. Front Sports Act Living 2021; 3:664231. [PMID: 34056590 PMCID: PMC8160372 DOI: 10.3389/fspor.2021.664231] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 03/24/2021] [Indexed: 12/24/2022] Open
Abstract
Talent research has recommended that multidimensional assessments of performance are needed to improve the identification and development of talented young athletes. However, factors such as the relative age effect may cloud our ability to assess factors related to performance. The aim of this study was to determine the extent of any relationship between soccer players' chronological and relative age, and objective and subjective performance assessments. Data for highly talented male soccer players selected into the German Soccer Associations' talent promotion program (N = 16,138) for U12 to U15 age groups (M age = 12.62 ± 1.04 years) were examined. Besides anthropometric assessments, players completed a battery of five motor tests that objectively assessed speed abilities and technical skills (specifically sprint, agility, dribbling, ball control, and juggling). In addition, coaches subjectively rated players on their kicking, tactical, and psychosocial skills, as well as providing holistic evaluations of each player's current and future performance levels. Correlation analyses were used to investigate the extent of any relationships between the chronological and relative age of players and their results for each of the assessments. A strong linear decrease in the frequency of later-born players confirmed the overrepresentation of early-born players in all age groups (0.92 ≤ |r| ≤ 0.95, each p < 0.001). From U12 to U15, significant (each p < 0.001) correlations were found between the chronological age of players and their height (|r| = 0.70), weight (|r| = 0.69), speed abilities (|r| = 0.38), and technical skills (|r| = 0.43). When evaluating each age group separately, small effects were found when correlating relative age with the anthropometric assessments (0.18 ≤ |r| ≤ 0.26), and only trivial effects with speed abilities and technical skills (0.01 ≤ |r| ≤ 0.06). Similarly, low correlations were found for the subjective evaluations of kicking, tactical, and psychosocial skills with chronological age across age groups (0.03 ≤ |r| ≤ 0.07), and with relative age in each age group (0.01 ≤ |r| ≤ 0.11). The results show a skewed distribution toward early-born players and-in reference to their relative age-advanced performance in late-born athletes. However, trends toward a better holistic rating of early-born players for current and future performance levels were found. Coaches should be aware of these effects during talent selection, but also when interpreting results from subjective and objective assessments of performance.
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Affiliation(s)
- Daniel Leyhr
- Department of Sport Psychology and Research Methods, Institute of Sports Science, Eberhard Karls University of Tübingen, Tübingen, Germany
- Methods Center, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Fynn Bergmann
- Department of Sport Psychology and Research Methods, Institute of Sports Science, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Robert Schreiner
- Department of Sport Psychology and Research Methods, Institute of Sports Science, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - David Mann
- Department of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | | | - Oliver Höner
- Department of Sport Psychology and Research Methods, Institute of Sports Science, Eberhard Karls University of Tübingen, Tübingen, Germany
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