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1.
Abstract

The birth date distributions of elite male and female footballers in Australia, from junior youth (age 14 and upwards) to senior (professional) players, were examined. A statistically significant relative age effect was found among junior male players, reducing in effect with increasing age. An inter-year relative age effect that became apparent among the players at national level in the Under-17 and Under-20 age groups, due to the timing of the respective World Cups for those age groups, was also identified. It is conjectured that this might lead to players born in certain years having a curtailed pathway in the elite game, leading to drop-out among this very elite group. In the case of women elite players, no significant relative age effect was found among youth players, possibly due to less fierce competition for places, although a significant effect was found to exist at senior elite level.  相似文献   

2.
Spain is one of the largest and most successful powers in international youth football, but this success has not extended to the national team. This lack of continued success seems to indicate a loss of potential. The relative age effect has been detected in football in many countries. Understanding the extent of this bias in the youth teams of Spanish elite clubs may help to improve selection processes and reduce the waste of potential. Comparisons between players from: the Spanish Professional Football League, all age categories of these clubs' youth teams, the Under-17 to Under-21 national teams, the national team, and the Spanish population, show a constant tendency to under-represent players from the later months of the selection year at all age groups of youth and Under-17 to Under-21 national teams. Professional and national team players show a similar but diminished behaviour that weakens with ageing, which suggests that talent identification and selection processes can be improved to help better identify potential talent early on and minimize wasted potential.  相似文献   

3.
Abstract

Spain is one of the largest and most successful powers in international youth football, but this success has not extended to the national team. This lack of continued success seems to indicate a loss of potential. The relative age effect has been detected in football in many countries. Understanding the extent of this bias in the youth teams of Spanish elite clubs may help to improve selection processes and reduce the waste of potential. Comparisons between players from: the Spanish Professional Football League, all age categories of these clubs' youth teams, the Under-17 to Under-21 national teams, the national team, and the Spanish population, show a constant tendency to under-represent players from the later months of the selection year at all age groups of youth and Under-17 to Under-21 national teams. Professional and national team players show a similar but diminished behaviour that weakens with ageing, which suggests that talent identification and selection processes can be improved to help better identify potential talent early on and minimize wasted potential.  相似文献   

4.
Season of birth distribution of elite tennis players   总被引：1，自引：0，他引：1  
In many competitive sports, the use of a cut-off date for junior competition has been associated with a skewed birth date distribution in junior and senior players. The International Tennis Federation uses a junior competition year that commences on 1 January. The purpose of the current investigation was to describe the birth date distribution of 448 elite senior tennis players and 476 elite junior tennis players. There was a significant season of birth bias among elite senior players (P < 0.001), with 58.9% being born in the first 6 months of the year. There was also a significant season of birth bias among elite junior players (P < 0.001), with 59.5% being born in the first 6 months of the year. This pattern was observed in both male and female players as well as in players from different regions. The results provide evidence that it is the cut-off date for the junior competition year that is responsible for the skewed birth date distribution in tennis rather than regional or climatic factors.  相似文献   

5.
In many competitive sports, the use of a cut-off date for junior competition has been associated with a skewed birth date distribution in junior and senior players. The International Tennis Federation uses a junior competition year that commences on 1 January. The purpose of the current investigation was to describe the birth date distribution of 448 elite senior tennis players and 476 elite junior tennis players. There was a significant season of birth bias among elite senior players (P <?0.001), with 58.9% being born in the first 6 months of the year. There was also a significant season of birth bias among elite junior players (P <?0.001), with 59.5% being born in the first 6 months of the year. This pattern was observed in both male and female players as well as in players from different regions. The results provide evidence that it is the cut-off date for the junior competition year that is responsible for the skewed birth date distribution in tennis rather than regional or climatic factors.  相似文献   

6.
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7.
Abstract

The relative age effect is an uneven distribution of birth date favouring subjects born in the initial months of a selection year. This study compared the birth-date distributions between several subgroups of Basque football players to identify whether the relative age effect is influenced by age and/or skill level. The study comprised 13,519 players including 114 senior professionals from the Spanish league's AC Bilbao over 21 seasons; over the season 2005–2006, it comprised elite youth (n = 189) from the same club's academy; regional youth (n = 4382) U11–U14 locally federated players; school youth (n = 8834) U10–U11 locally registered school district players. Differences between the observed and expected birth-date distributions were tested based on data from the general Basque male population. Significant chi-square values were followed up by calculating odds ratios and 95% confidence intervals (CI) for the quartile and half-year distributions to examine subgroup differences in the relative age effect. Birth-date distributions of all groups of players showed a significant bias towards early birth in the selection year compared with the reference population (senior, χ2 3 = 24.4, P < 0.001; elite youth, χ2 3 = 59.1, P < 0.001; regional youth, χ2 3 = 41.4, P < 0.001; school youth, χ2 3 = 40.9, P < 0.001). Between-group comparison revealed that the relative age effect incidence progressively increased with a higher level of involvement in youth football. This bias represents a significant loss of potential youth football talent.  相似文献   

8.
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9.
运用文献资料法、数理统计法,以2018—2021年上海市青少年校园足球精英赛运动员为研究对象,从历时性角度探究不同年龄组别和退出精英赛运动员的相对年龄效应特征及成因。发现除高中组女足运动员外,精英赛各组别均存在显著的相对年龄效应;在比赛位置上,男足前锋和守门员的效应尤为突出,且女足不同位置的出生季度分布同样差异显著;从退出情况看,相对年龄较大的U15和高中组男足运动员退出精英赛的可能性较高,而女足不受其影响。相对年龄效应引发的选材偏见普遍存在于上海市校园足球活动中,尤其是对不同性别和比赛位置均有显著影响,但相对年龄较大的男足运动员同样面临着较高的退出风险。为调控其影响,应对相关从业者开展充分的认知培训,更新现有知识和培养理念,在实践中优化选材成效。  相似文献   

10.
Talent identification at a young age is deemed essential for many national sporting organisations to increase the chances of success for their players on the international stage. Talent identification methods can be imprecise and national tennis associations and coaches often identify talent based on performances at youth tournaments and junior rankings. However, not much is known about the relationship between the international competition performances of young tennis players and later success. This relationship is explored in this study using comparisons based on: (a) the results of 3521 players at U14 youth tournaments; (b) the rankings of 377 junior players (U18) by the International Tennis Federation; (c) the rankings of 727 professional male players by the Association of Tennis Professionals; and (d) the rankings of 779 professional players by the Women's Tennis Association. Junior performances (U18) and performances at youth tournaments (U14) appear to have a low success rate in predicting later success. No distinct age was found at which players should start to perform in order to be successful at the professional level. It is concluded that even though good performances at young ages increase athletes’ chances to become elite players, they are not a precondition for achieving later success. Therefore, this study informs talent scouts, sport development officers, coaches and high performance managers of the role that performances at international youth competitions may play in talent identification in tennis.  相似文献   

11.
The primary purpose of this study was to investigate the effect of the place of early development in a sample of Danish male elite and youth handball and football players. The sample included 366 handball and football players from the elite Danish league in the season 2011–2012 and a comparison sample of youth players under the age of 12 from 2003, including 147,221 football and 26,290 handball players. Odds ratio analysis showed that both population size and density significantly affected the proportional number of youth players per community and the odds of athletes reaching an elite level in football and handball. The odds for youth player registrations in both handball and football increased in rural in contrast to urban communities. However, elite football players primarily came from communities of high density (>1000 pop./km2), whereas elite handball players primarily came from less densely populated communities (100 to <250 pop./km2). Furthermore, there seems to be a relation between representation of elite and talent clubs in different communities and the probability of becoming an elite player in both sports. The limited number of elite players in both sports from rural communities may be due to national talent development strategies that do not incorporate development support for clubs in rural areas. Additionally, the results of the study clearly suggest the need to include the youth player population to advance research findings in birthplace effect studies.  相似文献   

12.
Abstract

This study explored to which extent the development of German professional football players is based on early talent identification (TID) and long-term nurture in talent promotion (TP) programmes or on their emergence in the course of repeated procedures of player selection and de-selection in these programmes through childhood and youth. The annual turnover of squad members in national junior teams (2001–2013) and youth elite academies was calculated; national U-team members were followed up with regard to nominations through subsequent seasons and to their success level eventually achieved at senior age; and all current Bundesliga players were analysed retrospectively regarding their earlier involvement in TID/TP programmes. Analyses revealed that the mean annual turnover of squad members was 24.5% (youth academies) and 41.0% (national U-teams), respectively. At any age, the probability of persisting in the programme three years later was <50%. Among current Bundesliga players, the age of recruitment into the TID/TP programme was widely evenly distributed across childhood and youth, respectively. Accordingly, the number of (future) Bundesliga players who were involved in TID/TP was built up continuously through all age categories. The observations suggest that the collective of professional players emerged from repeated procedures of selection and de-selection through childhood and youth rather than from early selection and long-term continuous nurture in TID/TP programmes. The findings are discussed with regard to the uncertainty of TID and of interventions applied to the selected players, and they are related to the individualistic and collectivistic approach in TP.  相似文献   

13.
Asymmetries in the distributions of birth dates in senior professional and youth soccer players have been interpreted as evidence for systematic discrimination against individuals born shortly before the cut-off date in assigning youth to specific age groups. This concept is known as the “relative age effect”. The results of a longitudinal study of birth date distritubions of 2757 semi-professional and amateur senior soccer players in Belgium are presented. Records for competitive games were available in official statistics provided by the Royal Belgian Football Association. The chi-square statistic was used to examine differences between observed and expected birth date distributions. Regression analyses indicated a shift of bias when two different start dates were compared. Players born in the early part of the new age band (January to March) were over-represented compared with players born late in the new selection period (October to December). However, players with birthdays at the start of the old selection year (August) were still represented. In a retrospective analysis of 2138 players, variables indicative of match involvement, number of selections for matches, and time played were examined in relation to the relative age effect. The group of semi-professional and amateur senior soccer players born in the first quarter of the selected age band received more playing opportunities. Comparisons of birth date distributions (traditional approach to relative age effect) with match-related variables gave similar, though not entirely consistent, results. However, there were no differences for the mean number of selections and for playing minutes between players born at the start or the end of the selection year. Our findings suggest that match-based variables may provide a more reliable indication of the relative age effect in soccer.  相似文献   

14.
The relative age effect in soccer: a match-related perspective   总被引：1，自引：1，他引：0  
Asymmetries in the distributions of birth dates in senior professional and youth soccer players have been interpreted as evidence for systematic discrimination against individuals born shortly before the cut-off date in assigning youth to specific age groups. This concept is known as the "relative age effect". The results of a longitudinal study of birth date distritubions of 2757 semi-professional and amateur senior soccer players in Belgium are presented. Records for competitive games were available in official statistics provided by the Royal Belgian Football Association. The chi-square statistic was used to examine differences between observed and expected birth date distributions. Regression analyses indicated a shift of bias when two different start dates were compared. Players born in the early part of the new age band (January to March) were over-represented compared with players born late in the new selection period (October to December). However, players with birthdays at the start of the old selection year (August) were still represented. In a retrospective analysis of 2138 players, variables indicative of match involvement, number of selections for matches, and time played were examined in relation to the relative age effect. The group of semi-professional and amateur senior soccer players born in the first quarter of the selected age band received more playing opportunities. Comparisons of birth date distributions (traditional approach to relative age effect) with match-related variables gave similar, though not entirely consistent, results. However, there were no differences for the mean number of selections and for playing minutes between players born at the start or the end of the selection year. Our findings suggest that match-based variables may provide a more reliable indication of the relative age effect in soccer.  相似文献   

15.
The purpose of this study was twofold: (1) to determine the gross motor coordination performance levels of junior tennis players and (2) to analyse the effects of age and gender. Participants were junior male (n = 50) and female (n = 51) tennis players aged 6–14. Körperkoordinationstest für Kinder (KTK) was used to assess the gross motor coordination of the participants. Results revealed that none of the participants performed lower than normal level in motor coordination. Besides, 40.6% of the participants performed above normal level. No gender differences were found on all subtests of KTK and also on total motor quotient. Although older players performed better on each test than their younger counterparts for the raw scores, no significant age effect was observed on motor quotient scores among different age groups.  相似文献   

16.
ABSTRACT

This systematic review and meta-analysis aimed to determine differences in body compositionn between playing standard and age in male rugby union and rugby league athletes. The MOOSE (Meta-analysis of Observational Studies in Epidemiology) guidelines for design, implementation, and reporting were followed. Studies were required to be in male rugby union or league and have body composition as the primary or secondary outcome. Data was required to be presented separately for positional groups and body composition presented as whole-body. A systematic search was performed in PubMed, Cochrane Library, MEDLINE, SPORTDiscus, and CINHAHL via EBSCOhost. 57 studies were included for meta-analysis. Results highlighted significantly higher fat-free mass in senior elite than senior sub-elite or junior elite athletes for all RU and RL forwards. Small and non-significant differences were found in fat mass between rugby union playing standards and age categories. Rugby league senior elite forwards had less fat mass than junior elite forwards. Practitioners should prioritise training and nutritional strategies that maximise fat-free mass development, especially in junior elite cohorts.  相似文献   

17.
Abstract

Release velocity and accuracy are vital components of throwing performance. However, there is no published research on these parameters for throwing in cricket. In this study, we investigated the throwing performance of 110 cricket players from six different populations: elite senior males, elite under-19 junior males, elite under-17 junior males, elite senior females, elite under-19 junior females, and sub-elite senior males. Based on a specifically designed cricket throwing test, participants were assessed for (1) maximal throwing velocity and (2) throwing accuracy at maximal velocity and at three sub-maximal velocities. Elite senior males exhibited the highest peak and mean maximal throwing velocities (P≤0.001). Furthermore, the groups of males had significantly higher peak and mean maximal throwing velocities than the groups of females (P≤0.01). A speed–accuracy trade-off existed such that all groups demonstrated improved accuracy scores at velocities between 75% and 85% maximal throwing velocity compared with 50% maximal throwing velocity and 100% perceived maximal exertion. The results indicate that sex, training experience (years training), and training volume (training time per week) may contribute to throwing performance in cricket players. Further research should focus on understanding the mechanisms behind the observed differences between these groups. This is the first study to describe the inherent throwing profiles of different cricket playing populations. Potentially, we have identified stimulus material for future training developments.  相似文献   

18.
This study compared the whole-body movement coordination of pitching among 72 baseball players of various ages and velocity levels. Participants were classified as senior, junior, and little according to their age, with each group comprising 24 players. The velocity levels of the high-velocity (the top eight) and low-velocity (the lowest eight) groups were classified according to their pitching velocity. During pitching, the coordinates of 15 markers attached to the major joints of the whole-body movement system were collected for analysis. Sixteen kinematic parameters were calculated to compare the groups and velocity levels. Principal component analysis (PCA) was conducted to quantify the coordination pattern of pitching movement. The results were as follows: (1) five position and two velocity parameters significantly differed among the age groups, and two position and one velocity parameters significantly differed between the high- and low-velocity groups. (2) The coordination patterns of pitching movement could be described using three components, of which the eigenvalues and contents varied according to age and velocity level. In conclusion, the senior and junior players showed greater elbow angular velocity, whereas the little players exhibited a wider shoulder angle only at the beginning of pitching. The players with high velocity exhibited higher trunk and shoulder rotation velocity. The variations among groups found using PCA and kinematics parameter analyses were consistent.  相似文献   

19.
When placed into age groups for junior sporting competition, the relative differences in age between children leads to a bias in who is evaluated as being talented. While the impact of this relative age effect (RAE) is clear, until now there has been no evidence to show how to reduce it. The aim of this study was to determine whether the selection bias associated with the RAE could be reduced. Talent scouts from an elite football club watched junior games and ranked players on the basis of their potential. Scouts were allocated to one of three groups provided with contrasting information about the age of the players: (1) no age information, (2) players’ birthdates or (3) knowledge that the numbers on the playing shirts corresponded to the relative age of the players. Results revealed a significant selection bias for the scouts in the no-age information group, and that bias remained when scouts knew the players’ dates-of-birth. Strikingly though, the selection bias was eliminated when scouts watched the games knowing the shirt numbers corresponded to the relative ages of the players. The selection bias associated with the RAE can be reduced if information about age is presented appropriately.  相似文献   

20.
To determine the relationship between multidimensional performance characteristics and level of performance in talented youth field hockey players, elite youth players (n = 38, mean age 13.2 years, s = 1.26) were compared with sub-elite youth players (n = 88, mean age 14.2 years, s = 1.26) on anthropometric, physiological, technical, tactical and psychological characteristics. Multivariate analyses with performance level and gender as factors, and age as the covariate, showed that the elite youth players scored better than the sub-elite youth players on technical (dribble performance in a peak and repeated shuttle run), tactical (general tactics; tactics for possession and non-possession of the ball) and psychological variables (motivation) (P < 0.05). The most discriminating variables were tactics for possession of the ball, motivation and performance in a slalom dribble. Age discriminated between the two groups, indicating that the elite youth players were younger than the sub-elite players. In the guidance of young talented players to the top as well as in the detection of talented players, more attention has to be paid to tactical qualities, motivation and specific technical skills.  相似文献   

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