The relationships between relative age effect, personality constructs and achievement level in soccer.

Introduction: Youth soccer academies are challenged with the constant recruitment process of young talented players to select those who will achieve long-term success as an athlete. Youth soccer academies strive to enhance the physical and technical skill development as well as personality development of talented players because psychological characteristics play a crucial role in players' future success in their transition to professional soccer. The least mature players and relatively young players may have a greater need to possess superior technical/tactical or psycho-behavioral skills than those relatively older counterparts because of the higher selection rates of early maturing players. Due to RAEs, a significant decrease in the overall quality of professional soccer teams might be observed because of the loss of talent of physically smaller, but psychologically stronger and more versatile relatively young players who possess proper technical and tactical attributes at an early age. The first objective of this study was to examine any possible relationship between RAE and personality constructs. A second objective was to identify factors and effects that can help in the further improvement of talent selection and equal opportunities for elite youth soccer players based on their underlying RAE. The third objective was to consider the impact of RAE on long-term career development. Methods: In this retrospective observational study, 151 elite youth soccer players between 15 and 18 years of age were first grouped in birth quartiles. Personality constructs were then assessed, using a combination of observations, interviews, and a self-assessment questionnaire. Next competition level after 8 years was evaluated to identify RAEs, differences in personality characteristics and opportunities to reach professional soccer player status between relatively older vs. younger players. Results: A clear significant RAE was observed for the whole database (Q1 = 38.4% vs. Q4 = 13.9%) with OR of 2.61 (χ2 = 19.46, p < 0.01, r = -0.85). Relatively young players had higher median scores on personality constructs such as self-confidence (p = 0.04), while relatively old players had higher median scores on personality constructs such as team orientation (p = 0.03). In the long term, more players of the youngest birth quartile were signed as professional players (76.2%), compared with relatively old players (46.6%). 65.0% of the 20 players had the highest total score on personality constructs developed as a professional soccer player, vs. 35.0% of the 20 players with the lowest scores. Discussion: In conclusion, this study showed not only further evidence of the RAE but also provided evidence supporting "the underdog hypothesis" in national elite youth teams. Relatively young players were also more likely to get higher value senior professional contracts in the long term. We propose that this may be due to the relatively young players developing superior psychological skills and technical expertise to compensate for their early physical disadvantage. This in turn suggests the need for greater awareness of the importance of personality constructs in the future development of youth elite soccer players. Therefore, the crux of the issue is how youth soccer academies elicit the "best of both worlds" ie. moderating RAE whilst also gaining the benefits of the underdog hypothesis by creating the right environment for every player to develop to their full potential in elite youth soccer academies.

Leveling the Playing Field: A New Proposed Method to Address Relative Age- and Maturity-Related Bias in UK Male Academy Soccer Players.

Relative age selection bias persists within all major soccer leagues and youth soccer academies across the globe, with the relative age effect (RAE) being typically characterized as the over selection of relatively older players (who have sometimes also been shown to be early maturing). The aim of this study was to examine if a new allocation method (i) eliminates the RAE, and (ii) reduces the presence of any additional maturity-related differences in anthropometric and physical fitness characteristics which may exist between players within the same selection category. In the first phase, 1,003 academy soccer players [under (U) 9-16] from 23 UK professional soccer clubs were sampled and a clear RAE per birth quarter (Q) was observed for the overall sample (Q1 = 45.0% vs. Q4 = 9.8%) as well as for the different age categories. Using the newly suggested reallocation method, youth players were divided by allocation date which was defined as the midway point between the chronological age and the estimated developmental (ED) birthdate. Stature was used as an anthropometric reference point on the P50 of the growth curve to determine the developmental birthdate for this new method. After the reallocation of the players using ED, the distribution of players was more equally spread (Q1 = 25.3%, Q2 = 25.6%, Q3 = 22.4%, Q4 = 26.7%). After reallocation, the mean delta stature was reduced by 16.6 cm (from 40.3 ± 7.08 to 23.7 ± 4.09 cm, d = 2.87). The mean delta body mass difference after allocation was reduced by 6.7kg (from 33.2 ± 6.39 to 26.5 ± 4.85 kg, d = 1.18). The mean age difference increased from 1.8 to 3.9 years. A total of 42.7% of the sample would have been reallocated to a different age group compared to the current one. After reallocation, 45% of the anthropometric and physical fitness comparisons showed reductions in the within-group variation expressed as a percentage of coefficient of variation (CV%). The U10 players demonstrated the largest reduction in CV% (-7.6%) of the anthropometric characteristics. The U10 squad also showed the largest reduction in CV% for various physical fitness characteristics (-7.5%). By both eliminating the RAE and reducing temporary maturity-related anthropometric and physical fitness differences, soccer academies across the world may diversify and increase the size of the talent pool both for clubs and national youth teams. In conclusion, this study provides further evidence that the newly proposed allocation method shows the potential to remove the RAE and to create a more "leveled playing field" by reducing the within-group variation of anthropometric and physical fitness characteristics affording relatively younger, and eventually, late-maturing players the opportunity to develop their talent fairly.

Leveling the Playing Field: A New Proposed Method to Address Relative Age- and Maturity-Related Bias in Soccer.

Despite various solutions proposed to solve the relative age effect (RAE), it is still a major problem confounding talent identification and selection processes. In the first phase, we sampled 302 under 7-21 academy soccer players from two Belgian professional soccer clubs to explore the potential of a new approach to solve the inequalities resulting from relative age- and maturity-related bias. This approach allocates players into four discrete quartile groups based on the midway point of their chronological and estimated developmental (ED) birth dates (calculated using the growth curves for stature of Belgian youth). With the use of chi square analyses, a RAE was found (p < 0.01) for the overall sample (Q1 = 41.4% vs. Q4 = 14.9%) that completely disappeared after reallocation (Q1 = 26.5%; Q2 = 21.9%; Q3 = 27.5%; Q4 = 24.2%). According to the new allocation method, the stature difference was reduced, on average, by 11.6 cm (from 24.0 ± 9.9 to 12.4 ± 3.4 cm, d = 1.57). Body mass difference between the two methods was 1.9 kg (20.1 ± 11.3-18.2 ± 13.1 kg, respectively, d = 0.15). The new method created a maximum chronological age difference of 1.9 vs. 0.8 years for the current method. With the use of this method, 47% of the players would be reallocated. Twenty-three percent would be moved up one age category, and 21% would be moved down. In the second phase, we also examined 80 UK academy soccer players to explore if reallocating players reduces the within-playing group variation of somatic and physical fitness characteristics. The percentage coefficient of variation (%CV) was reduced (0.2-10.1%) in 15 out of 20 metrics across U11-U16 age categories, with the U13 age category demonstrating the largest reductions (0.9-10.1%) in CV. The U12 and U13 age categories and associated reallocation groupings showed trivial to small (ES = 0.0-0.5) between-method differences and trivial to moderate (ES = 0.0-1.1) differences within the U14-U16 age categories. A reduction in RAE may lead to fewer dropouts and thus a larger player pool, which benefits, in turn, talent identification, selection, and development.

The Constituent Year Effect in European Track and Field Masters Athletes: Evidence of Participation and Performance Advantages.

Inequalities in relative age distribution have previously been demonstrated to influence participation and performance achievements in Masters athletes. The purpose of the present study was to examine the participation- and performance-related constituent year effect among Masters athletes (N = 2,474) from the European Masters Track and Field Championships across subdisciplines and age. The results indicated that a participation-related constituent year effect was observed. The likelihood of participation was significantly higher for athletes in their first year of any 5-year age category (χ2 = 149.8, p < .001) and decreased significantly when they were in the fourth or fifth year. The results also indicated a performance-related constituent year effect. Masters athletes in their first year won significantly more medals than expected based on observed participation rate (χ2 = 23.39, p < .001). We compare our results with the existing literature and discuss potential mechanisms for this constituent year effect.

Gender, age, and sport differences in relative age effects among US Masters swimming and track and field athletes.

A relative age effect has been identified in Masters sports (Medic, Starkes, & Young, 2007). Since gender, age, and type of sport have been found to influence the relative age effect in youth sports (Musch & Grondin, 2001), we examined how these three variables influenced possible relative age effects among Masters swimmers and track and field athletes. Using archived data between 1996 and 2006, frequency of participation entries and record-setting performances at the US Masters championships were examined as a function of an individual's constituent year within any 5-year age category. Study 1 investigated the frequency of Master athletes who participated; Study 2 examined the frequency of performance records that were set across constituent years within an age category, while accounting for the distribution of participation frequencies. Results showed that a participation-related relative age effect in Masters sports is stronger for males, that it becomes progressively stronger with each successive decade of life, and that it does not differ across track and field and swimming. In addition, a performance-related relative age effect in Masters sport seems to be stronger for swimming than track and field, but it does not differ across gender and decades of life.

Contextual influences on baseball ball-strike decisions in umpires, players, and controls.

Baseball umpires, players, and control participants with no baseball experience were asked to call balls and strikes for video clips. In a basic judgement task, umpires and players were significantly better at calling pitches than controls. In a direct information task, borderline pitches were presented following clips of definite balls and definite strikes. Participants called target pitches closer to the strike end of the scale when viewed after definite balls than when they followed definite strikes. Similarly, when borderline pitches were shown in different pitch counts, participants called pitches more towards the strike end of the scale when there were three balls in the count (3-0, 3-2). These findings indicate that the standard for evaluation changes based on the context in which stimuli are processed. Moreover, the strength of the contextual factors is illustrated in that the effects were shown in observers with and without experience in the task. Overall, however, umpires had a greater tendency to call strikes, indicating that they may use a norm of "hastening the game".

Does lifelong training temper age-related decline in sport performance? Interpreting differences between cross-sectional and longitudinal data.

In the face of remarkable aging trends in North American society, organized sport/physical activity is an important vehicle for promoting physical health, and a domain in which long-term participation might mitigate pessimistic trends for age decline. This investigation examined patterns of age-related decline in performance for 45 Masters runners who rigorously trained continuously for at least a decade. Longitudinal data for age and performance were collected for 200 m, 1500 m, and 10 km events retrospectively across participants' careers. Cross-sectional (CS) data representing normal patterns of aging were derived from online archives. Longitudinal data reflected within-participant training effects whereas CS data did not. Second-order regression analyses were performed separately for each data type and quadratic beta coefficients, indicative of accelerated age decline, were compared for CS and longitudinal samples on a within-event basis. Results showed evidence of accelerated decline with advancing age for both samples, although rates for longitudinal samples were moderated for the 200 m and 1500 m events. Findings for the long-distance event were anomalous. Results provide evidence for moderated age-decline in physical performance measures for individuals who sustain engagement in organized sport for lengthy periods. Discussion focuses on methodological considerations for advancing future research that contrasts CS and longitudinal samples, and the importance of encouraging sport involvement opportunities to aging individuals.

Explaining performance in elite middle-aged runners: contributions from age and from ongoing and past training factors.

Researchers have contended that patterns of age-related decline are not necessarily due to age, but rather to disuse, or declining practice (Bortz, 1982; Ericsson, 2000; Maharam, Bauman, Kalman, Skolnik, & Perle, 1999). A regression approach was used to examine age and training variables as predictors of 10-km running performance between 40 and 59 years of age. A sample of 30 Masters runners (M age=50.1 years, M 10-km time=39:19) reported data for ongoing training, cumulative running in the past 5 years, and cumulative running earlier in a career. In Analysis 1, ongoing training variables explained more variance in performance than age alone, and reduced the unique variance attributable to age in a combined model. In Analysis 2, findings were replicated using past cumulative running variables and age; running in the past 5 years explained more unique variance than age alone. Discussion focuses on how findings relate to the selective maintenance account (Krampe & Ericsson, 1996), how various aspects of training help to preserve performance in aging populations, and recommendations for future research.

Examining relative age effects on performance achievement and participation rates in Masters athletes.

Although the relative age effect has been widely observed in youth sports (Musch & Grondin, 2001), it is unclear whether it generalizes across the lifespan. The purpose of this study was to examine the relative age effect among a population of Masters athletes using archived data. Two successive studies examined the frequency of record-setting achievements (Study 1) and the frequency of participation entries (Study 2) at the US Masters track-and-field and swimming championships as a function of an individual's constituent year within any 5-year age category. Results of Study 1 indicated that the probability of setting a record increased if Masters athletes were in the first year, and decreased if they were in the third, fourth or fifth year, of an age category. Results of Study 2 indicated that the likelihood of participating in the National championships increased if Masters athletes were in the first or second year, and decreased if they were in the fourth or fifth year, of an age category. We highlight and discuss potential advantages afforded to Masters athletes who are relatively younger than their peers in the same 5-year age category.

Decision-making skills and deliberate practice in elite association football referees.

We examined sport expertise as a function of role. In study 1, referees were better than players in a video-based decision-making task. This provides evidence that there are role-specific skills within one domain or sport. In study 2, we examined the training activities that could be influential in the development of skills in sports officials. Elite association football (soccer) referees retrospectively reported time spent in and perceptions of training activities for three periods: their first year of formal refereeing, 1998 (before formal training programmes were available), and the current year (2003). This allowed us to examine an area of skill with a limited culture of practice, where performance simulations with direct feedback are usually not feasible. The results showed that referees specialize early and, as they develop, they engage in greater volumes and types of training. Competitive match refereeing is considered a relevant activity for skill acquisition that does not fit Ericsson and colleagues' (1993) original definition of deliberate practice. Our findings indicate that actual performance is a significant activity for skill acquisition and refinement.

Deliberate imagery practice: the reliability of using a retrospective recall methodology.

This study examined the reliability of a retrospective recall methodology for providing evidence of deliberate imagery practice. A secondary purpose was to determine which imagery activities constituted the sport-specific definition of deliberate practice (Starkes, Deakin, Allard, Hodges, & Hayes, 1996). Ninety-three Canadian athletes from one of three different competitive levels (regional, provincial, and national) completed the Deliberate Imagery Practice Recall Questionnaire, which was specifically designed for the present study. The athletes also completed a 1-week imagery diary to assess their use of 14 different imagery activities. The results of the study indicated that the athletes were able to reliably estimate their use of imagery over a short recall interval. Four imagery activities were also determined to fulfill the sport specific definition of deliberate practice.

Career-span analyses of track performance: longitudinal data present a more optimistic view of age-related performance decline.

Sport scientists (Starkes, Weir, Singh, Hodges, & Kerr, 1999; Starkes, Weir, & Young, 2003) have suggested that prolonged training is critical for the maintenance of athletic performance even in the face of predicted age-related decline. This study used polynomial regression analyses to examine the relationship between age and running performance in the 1500 and 10,000 metre events. We compared the age and career-longitudinal performances for 15 male Canadian Masters athletes with a cross-sectional sample of performances at different ages. We hypothesized that the 30 years of uninterrupted training characteristic of this longitudinal sample would moderate the patterns of age-related decline (retention hypothesis); alternatively, the cross-sectional data were expected to demonstrate pronounced age-related decline (quadratic hypothesis). Investigators performed multimodel regression analyses on the age and performance data. Based on the absence (for longitudinal data) or presence (for the cross-sectional data) of significant quadratic components in second-order polynomial models, the authors found support for their respective hypotheses. The longitudinal data showed that running performance declined with age in a more linear fashion than did cross-sectional data. Graphical trends showed that the moderation of age-related decline appeared greater for the longitudinal 10 km performances than for the 1500m event.

Predicting performance times from deliberate practice hours for triathletes and swimmers: what, when, and where is practice important?

In Studies 1 and 2, the authors evaluated deliberate practice theory through analyses of the relationship between practice and performance for 2 populations of athletes: triathletes and swimmers, respectively. In Study 3, the authors obtained evaluations of practice from athletes' diaries. Across athletes, length of time involved in fitness activities was not related to performance. For the triathletes, a significant percentage of variance in performance was captured by practice. This was not so for sprint events for the swimmers, in which gender was a significant predictor. In the diaries, physical activities were perceived as enjoyable. In contrast to the results obtained from questionnaires, enjoyment did not covary with an activity's relevance to improving performance. Although these findings highlight the importance of sport-specific practice, the authors question a domain-independent account of expertise based on deliberate practice.

Gender differences in perception of self-orientation: software or hardware?

We evaluated the contribution of attentional strategy to the perception of self-orientation with and without a body tilt in the median plane. Reinking et al (1974 Journal of Personality and Social Psychology 30 807-811) found that the frame dependence of females on the rod-and-frame test could be mediated by instructions prompting them to focus on internal cues (ie arising from inside of the body). Here, we measured the influence of attentional instructions on the perception of the morphological horizon. Eleven females and thirteen males estimated their morphological horizon in an upright and a 45 degrees body tilt in the median plane under three instruction conditions. All participants first performed without attentional instructions. Then, participants performed under both internal and external attentional instructions. For females, but not for males, perception of morphological horizon was more footward in the supine than in the upright orientation. Although instructions did not eliminate gender differences, internal instructions allowed females to reduce their perceptual bias in the supine orientation.

Learning to use minimal access surgical instruments and 2-dimensional remote visual feedback: how difficult is the task for novices?

Performing minimal access surgery requires the use of 2-dimensional information to produce 3-dimensional movements, as well as precise motor control for manipulating laparoscopic tools. The added visuomotor demands of this task make it more demanding and complex than traditional open surgery. The purpose of this study was to determine the relative task difficulty of performing laparoscopic tool movements with normal vision or 'laparoscopic vision' provided by a remote 2-D monitor. A second purpose of this study was to evaluate whether movement performance changes are induced by practice with normal vision (NV) and laparoscopic vision (LV). The study was also designed to determine whether order of visual condition (NV or LV) practice impacts the rate of performance acquisition when transferred to the opposing visual condition. Eleven individuals participated in this study. All subjects performed a bean grasping and a suturing task in two visual conditions: normal vision and laparoscopic vision. Results revealed that laparoscopic tools themselves do not appear to be problematic in performing minimal access surgery. Furthermore, performance ability in normal vision does not positively transfer to performance when switched to a laparoscopic vision condition. The 2-dimensional video does appear to be problematic for skill acquisition, as performance levels decreased as complexity of the task increased.

When paying attention becomes counterproductive: impact of divided versus skill-focused attention on novice and experienced performance of sensorimotor skills.

Two experiments examined the impact of attention on sensorimotor skills. In Experiment 1, experienced golfers putted under dual-task conditions designed to distract attention from putting and under skill-focused conditions that prompted attention to step-by-step putting performance. Dual-task condition putting was more accurate. In Experiment 2, right-footed novice and experienced soccer players dribbled through a slalom course under dual-task or skill-focused conditions. When using their dominant right foot, experts again performed better in the dual-task condition. However, when using their less proficient left foot, experts performed better in the skill-focused condition. Novices performed better under skill-focus regardless of foot. Whereas novices and the less-proficient performances of experts benefit from online attentional monitoring of step-by-step performance, high-level skill execution is harmed.

Effect of a change in selection year on success in male soccer players.

Since 1997 and following the guidelines of the International Football Association, the Belgian Soccer Federation has used January 1st as the start of the selection year. Previously, August 1 was the start. This shift prompted an investigation of changes in birth-date distributions throughout youth categories for 1996-1997 compared to the 1997-1998 competitive years. Birth dates were considered for national youth league players, ages 10-12, 12-14, 14-16, and 16-18 years. Kolmogorov Smirnov tests assessed differences between observed and expected birth-date distributions. Regression analyses examined the relationship between month of birth and number of participants both before and after the August to January shift. Results indicated that from 1996 to 1997, youth players born from January to March (the early part of the new selection year) were more likely to be identified as "talented" and to be exposed to higher levels of coaching. In comparison, players born late in the new selection year (August to October) were assessed as "talented" in significantly lower proportions. Specific suggestions are presented to reduce the relative age effect. Am. J. Hum. Biol. 12:729-735, 2000. Copyright 2000 Wiley-Liss, Inc.

The influence of relative age on success and dropout in male soccer players.

The consistent asymmetry in the birth-date distribution of senior professional soccer players has led us to investigate whether similar asymmetries emerge throughout youth categories in soccer. Birth dates were considered for professional players, national youth teams, youth players transferred to top teams, and regular youth league players. Kolmogorov Smirnov tests assessed differences between observed and expected birth-date distributions. Regression analyses examined the relationship between month of birth and number of participants at various levels of play in soccer. Results indicated that youth players born from August to October (the early part of the selection year), beginning in the 6-8 year age group, are more likely to be identified as talented and to be exposed to higher levels of coaching. Eventually, these players are more likely to be transferred to top teams, to play for national teams, and to become involved professionally. In comparison, players born late in the selection year tended to dropout as early as 12 years of age. Recommendations suggest a review of the 24-month age band and current methods for talent detection and selection. Am. J. Hum. Biol. 10:791-798, 1998. © 1998 Wiley-Liss, Inc.