An unexpected shift in constant year effects in female elite handball.

One of the most convincing studies about the importance of the cutoff date in relative age effects was when Helsen et al. (2000) showed that a shift in the date directly resulted in a change of birth month distributions in soccer. Over the past four decades, the role of the birth year has also been associated with relative age effects (as reflected in constant year effects). In this investigation, two studies attempted to replicate the shift of birth year distributions caused by a change in birth years in international female handball. In Study 1, the results from the female handball world championship 2017 showed a significant within-year effect overall and a constant year effect for players born 1988 and after. A second study was conducted with female players from world championships in 2009, 2011, 2013, and 2015. Results demonstrated small effect sizes for most tests. However, there was an unexpected trend toward a constant year effect shift at the age of 28 years. Several hypotheses are presented as an explanation for this trend.

Training and development in sport officials: A systematic review.

Sport officials make significant contributions to organized sport, yet scientific evidence to inform their specialized training and education at various levels has lagged. While psychological and performance demands of expert sport officials have been well documented, the extent of research about talent and expertise development, training efficacy, and broader developmental trajectories is unclear. This systematic review summarizes 30 years of published findings on the study of training and development of sport officials, including areas of research interest, study designs, and sport official characteristics. A PRISMA systematic review was conducted, utilizing three scientific databases (Web of Science, SportsDiscus, PsycInfo) to identify relevant studies (N = 27). Female participants were generally underrepresented in studies (17%), while football officials were most often represented (79%). Training intervention (59%), retrospective (37%), and cross-sectional comparison (22%) were the main study designs. Expert and near-expert sport officials' training histories and responses to empirically driven isolated-skills training represented the predominant areas of study. Sport-specific, video-based infraction detection tasks were the most frequently used training methods to improve perceptual-cognitive skills for on-field decision-making, however, studies lacked retention measures to on-field performance. Psychological skills training programs were found to have mixed effects and used varied criteria for measuring training efficacy. Physical training showed mainly significant effects on physiological measures and aging influences for on-field performance. More rigorous sport-specific evidence, assessments of training transfer, program efficacy, and macro-developmental trajectory and milestone data are needed to inform training programs and developmental plans.

Survival Versus Attraction Advantages and Talent Selection in Sport.

Athlete selection (often referred to as talent selection) reflects the end point of what is a complex decision-making process coaches, administrators, and/or scouts use when deciding who remains and who is removed from a sample of potential athletes. In this paper, we conceptualize athlete selection as an evolutionary process where selection pressures (e.g., performance demands, system limitations) influence the value of one trait/characteristic over another. Athletes are selected either through demonstrating enhanced performance (survival advantages) or by having characteristics that are desirable to the coach/recruiter making the selection (attraction advantages). Based on these varying pressures, our understanding of whether profiles of current athletes represent the actual elements of performance necessary for success or simply those most needed for selection at key points in athlete development is extremely limited.

Talent Research in Sport 1990-2018: A Scoping Review.

Several recent systematic and targeted reviews have highlighted limitations in our understanding of talent in sport. However, a comprehensive profile of where the scientific research has focused would help identify gaps in current knowledge. Our goal in this scoping review was (a) to better understand what others have done in the field of research (e.g., what groups have been examined using what research designs and in what areas), (b) to summarize the constituent areas of research in a meaningful way, (c) to help identify gaps in the research, and (d) to encourage future research to address these gaps. Peer-reviewed articles written in English that met several inclusion criteria were analyzed. A total of 1,899 articles were identified, and the descriptive findings revealed a relatively narrow focus of research on talent in sport. Specifically, the majority of examined articles focused on (a) males only, (b) the sport of soccer, (c) perceptual cognitive variables, (d) developing athletes, (e) adult samples, and (f) cross-sectional designs. For better or worse, the concept of talent remains a central element of how coaches, practitioners, and scientists think about athlete development. Findings from this scoping review highlight the continued need to explore issues related to talent identification, selection, and development in more diverse samples (e.g., female athletes and younger ages) and contexts (e.g., from Africa, Asia, and South America). There is also a clear necessity to focus on under-researched areas using alternative methodologies.

Understanding the Development of Elite Parasport Athletes Using a Constraint-Led Approach: Considerations for Coaches and Practitioners.

For the past half-century, the Paralympic Games has continued to grow, evident through increased participation, media recognition, and rising research focus in Para sport. While the competitive pool of athletes has increased, athlete development models have stayed relatively the same. Currently, coaches rely mainly on experiential knowledge, informal communication with colleagues, and theory transferred from able-bodied contexts as main resources to support development for themselves and their athletes. The purpose of this paper was to introduce Newell's constraint-led model and its multidimensional spectrum and practical scope to address the complexities of athlete development. The model consists of three overarching constraint categories (i.e., individual, task, and environment) along with proposed additional sub-categories to capture nuances associated in Para sport in order to provide additional context to coaches regarding athlete development. Utilizing this theoretical framework, we present a holistic approach for coaches and practitioners to consider while addressing athletes' short- and long-term developmental plans. This approach highlights the interactions among factors from a wide range of categories that indirectly and directly impact one another and ultimately influence athletes' developmental processes. It is important to consider the dynamic interaction of constraints over various timescales during development and identify underlying issues to improve athlete experience and maximize developmental opportunities. Coaches and practitioners can use the proposed framework as a guide to key factors to consider for their cohort of athletes. This approach provides a context-specific approach that considers unique factors associated with athletes and their environment.

Relative age effects in Elite Chinese soccer players: Implications of the 'one-child' policy.

The relative age effect (RAE) refers to the asymmetrical distribution of birthdates in a cohort found in many achievement domains, particularly in sports with many participants like soccer. Given the uniqueness of the one-child policy in China, this study examined the existence of the RAE in elite Chinese male and female soccer players generally and relative to their playing position on the field. Results showed a clear and obvious RAE for all age groups (U20 male, U18 male, adult female and U18 female) with the observed birthdate distributions for each age group significantly different from expected distributions (p<0.05). Additionally, we noticed a differential RAE according to the players' position on the field as reflected in different effect sizes. In male players, the RAE was significantly greater in Defenders (DF) and Goalkeepers (GK) compared to Midfielders (MF) and Forwards (FW) (VDF = 0.266>VGK = 0.215>VMF = 0.178>VFW = 0.175). In female players, GKs had a larger RAE (VGK = 0.184>0.17, VDF = 0.143, VMF = 0.127, VFW = 0.116). To reduce the negative consequences associated with RAEs throughout player development systems, potential solutions are discussed.

Getting to First Base: Developmental Trajectories of Major League Baseball Players.

The road to professional baseball illustrates the complexity, variability and non-linearity of athlete development, as players may be drafted from various high school, 2 year, or 4 year programs and then placed into extensive minor league systems. The purpose of this study was to identify the different pathways to Major League Baseball (MLB) and explore their influence on career success. Performance and developmental data of 2,291 American-born MLB players who debuted between 1990 and 2010 were collected using baseball-reference.com. Three performance indicators, career games played (GP), age of debut, and wins above replacement (WAR; player's total contributions in wins), were coupled with high school, post-secondary, and Minor League Baseball (MiLB) data. Analyses revealed 17 descriptively different pathways to MLB, which were grouped into three main streams based on the last institution attended before entrance into professional baseball. Overall, 63% of the athletes started their career directly after attending a 4 year higher education institution, 23% after high school, and 14% directly after attending a 2 year institution. Interestingly, 78% of the athletes did not sign or were not selected as high school draft picks. Position players drafted or signed from high school debuted in MLB younger (M = 23.99) and averaged significantly more MiLB GP (M = 909.13) than those drafted or signed from a 2 year (M = 25.67 and 834.41 GP) or 4 year institution (M = 25.95 and 752.33 GP). Pitchers signed or drafted from high school also debuted in MLB younger and played more MiLB games, as well as played in more MLB games than players from a 2 year or 4 year institution, F(8, 3,082) = 31.96, p ≤ 0.001. No significant differences of WAR were noted in position players or pitchers. Perhaps pitchers who are drafted from high school are afforded more opportunities to succeed, which may be indicative of sunk cost effects. This is conceivable as these players had the highest average GP but did not accrue a higher WAR. Future research may benefit from the consideration of post-secondary and/or high school statistics in combination with draft selection data, which may have important implications for improving talent identification accuracy.

Understanding High Achievement: The Case for Eminence.

The development of the field of sport expertise over the past 20 years has been remarkable, and our understanding of the varying factors affecting athlete development and motor skill acquisition has expanded considerably. Recently, there has been a push toward more sophisticated research designs to continue the advancement of our understanding of sport expertise. Even in a population of performers at the highest levels of performance and competition (e.g., participants in professional sports or those who compete at Olympic Games), there are those with obvious superiority compared to others in the cohort, such as those who win "most valuable player" awards or who are elected to the Hall of Fame. This paper builds a case that athletes who reach this level of achievement possess a more advanced level of skill than those at the elite or expert stage and we refer to this stage of development as "eminence." This paper explores the notion of eminence and provides converging forms of evidence for the division between expertise and eminence. Moreover, it explores the implications of this division for the further examination of skill acquisition across the lifespan.

Population density and proximity to junior developmental teams affect the development of National Hockey League draftees.

Inconsistencies in community size effects found between and within countries (Baker et al Eur J Sport Sci. 2009;9:329-339; Bruner et al J Sports Sci. 2011;29:1337-1344; Wattie et al J Sports Sci. 2018;36:436-444) suggest population size may not be an accurate predictor of athlete development and that other proxies of early environmental characteristics are needed. Researchers have begun to explore the influence of population density and proximity to local sport clubs on athlete development in European countries; however, similar analysis remains to be conducted in Canadian ice hockey. The current study focused on National Hockey League (NHL) draftees and explored whether population density and proximity to Canadian Hockey League teams were associated with the number of draftees produced. Linear regression analyses showed a significant positive relationship between population density and the development of draftees in all provincial regions; however, a significant negative relationship between proximity to CHL teams and NHL draftee development was observed in four out of six provincial regions (British Columbia, Ontario, Quebec, and the Atlantic Provinces). Moreover, population density appeared to be a better predictor of NHL talent development than proximity to CHL teams. Future research may benefit from exploring the effects of these two variables within population size categories, as well as between different regions within provinces.

Vital statistics and early death predictors of North American professional basketball players: A historical examination.

While empirical evidence suggests that elite athletes have superior lifespan outcomes relative to the general population, less is known regarding their causes of death. The purpose of this study was to critically examine the mortality outcomes of deceased National Basketball Association and American Basketball Association players. Death data were collected from publicly available sources until 11 December 2015, and causes of death were categorized using the International Classification of Diseases, Tenth Revision (ICD). Mortality was measured through: i) cause-specific crude death rates (CDR), ii) estimates of death rates per athlete-year (AY), and iii) binary and multinomial regression analyses. We identified 514 causes of death from 787 deceased players (M = 68.1 y ± 16.0) from 16 different ICD groups, 432 of which were from natural causes. Findings showed similar leading causes of death and CDRs to sex- and race-matched controls, higher death rate differences per AY within time-dependent variables (i.e., birth decade, race, and height), and a higher likelihood of dying below the median age of death for black and taller players, although this was highly confounded by birth decade. More complete knowledge of mortality outcomes would provide broad public health applications and disarm harmful stereotypes of elite athlete health.

Talent Identification in Sport: A Systematic Review.

BACKGROUND: Talent identification (TID) programs are an integral part of the selection process for elite-level athletes. While many sport organizations utilize TID programs, there does not seem to be a clear set of variables that consistently predict future success. OBJECTIVE: This review aims to synthesize longitudinal and retrospective studies examining differences between performance variables in highly skilled and less-skilled athletes in elite-level sport. METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to identify relevant studies (N = 20). RESULTS: There was a clear overrepresentation of studies that (1) examined physical profiles of athletes (60%); (2) focused on male samples (65%); (3) examined athletes between the ages of 10 and 20 years (60%); and (4) were published between the years 2010 and 2015 (65%). On closer examination, there was a high degree of variability in the factors that were found to discriminate between skilled and less-skilled individuals. CONCLUSION: Findings from this review highlight how little is known about TID in elite sport and emphasize the need for greater diversity in TID research.

Seasonal Changes in Functional Fitness and Neurocognitive Assessments in Youth Ice-Hockey Players.

Avery, M, Wattie, N, Holmes, M, and Dogra, S. Seasonal changes in functional fitness and neurocognitive assessments in youth ice-hockey players. J Strength Cond Res 32(11): 3143-3152, 2018-Deficits in balance and strength combined with differing rates of sensory and motor neural development may increase risk of sports-related injury in youth. This study evaluated changes in functional fitness and concussion status over the course of a competitive season in youth ice-hockey players, and examined the relationship between these variables and injury occurrence. Thirty-six participants (8.9 ± 1.1 years) completed preseason and postseason assessments including anthropometric measurements, the functional movement screen (FMS), Lower Quarter Y-Balance Test (YBT-LQ), and a computerized neurocognitive assessment (ImPACT). Paired-samples t-tests were used to compare preseason and postseason data. Independent samples t-tests were used to compare FMS, YBT-LQ, and ImPACT scores between injured and uninjured participants at baseline. The mean composite score of the FMS was not statistically different between preseason (15.1 ± 1.8) and postseason (15.6 ± 2.3, p < 0.16). The YBT-LQ composite score showed a decrease in reach distance scores between preseason (86.10 ± 6.00) and postseason (83.20 ± 5.40, p < 0.001). Neurocognitive assessment scores improved in both the injured and uninjured participants. There were no significant relationships between FMS scores, YBT-LQ, and injury incidence. Results from our study provide insight into changes in functional fitness levels and neurocognitive scores over the course of a season in youth ice-hockey players. These findings provide insight into expected changes over the course of a season and provide context for injury risk monitoring by coaches.

Heterogeneity in Community Size Effects: Exploring Variations in the Production of National Hockey League Draftees Between Canadian Cities.

Previous research has explored 'community size effects' in a multitude of sporting and regional contexts and has shown that athletes are more likely to originate from small-medium population size categories, and less likely to originate from very small or large ones. However, it is not clear whether the production of athletes is homogenous within population size categories. Place of birth data were collected for all Canadian born hockey players drafted into the National Hockey League (NHL) from 2000-2014 from British Columbia (N = 192), Alberta (N = 218), Saskatchewan and Manitoba (N = 216), Ontario (N = 561), Quebec (N = 241), and the Atlantic Provinces (N = 74). To explore variations in the production of draftees within population size categories, proportions of productive cities, population mean (µ), population standard deviation (σ), as well as minimum/maximum values of the number of draftees were calculated for the different categories (<2,500; 2,500-4,999; 5,000-9,999; 10,000-29,999; 30,000-99,999; 100,000-249,999; 250,000-499,999; 500,000-999,999; >1,000,000). In addition, the number of draftees produced per 1,000 residents (i.e., yield) was calculated for each city within all categories. Results showed substantial intra-categorical variability in NHL talent development; moreover, heterogeneity in draftee production existed in various degrees across provincial regions of Canada. Intra-categorical variability suggests that a single homogenous community size effect may not exist for Canadian NHL draftees, and that future research may benefit from exploring other environmental constraints on athlete development such as income, population density, and proximity to local sport clubs.

Do "big guys" really die younger? An examination of height and lifespan in former professional basketball players.

While factors such as genetics may mediate the relationship between height and mortality, evidence suggests that larger body size may be an important risk indicator of reduced lifespan longevity in particular. This study critically examined this relationship in professional basketball players. We examined living and deceased players who have played in the National Basketball Association (debut between 1946-2010) and/or the American Basketball Association (1967-1976) using descriptive and Kaplan-Meier and Cox regression analyses. The cut-off date for death data collection was December 11, 2015. Overall, 3,901 living and deceased players were identified and had a mean height of 197.78 cm (± 9.29, Range: 160.02-231.14), and of those, 787 former players were identified as deceased with a mean height of 193.88 cm (± 8.83, Range: 167.6-228.6). Descriptive findings indicated that the tallest players (top 5%) died younger than the shortest players (bottom 5%) in all but one birth decade (1941-1950). Similarly, survival analyses showed a significant relationship between height and lifespan longevity when both dichotomizing [χ2 (1) = 13.04, p < .05] and trichotomizing [χ2 (2) = 18.05, p < .05] the predictor variable height per birth decade, where taller players had a significantly higher mortality risk compared to shorter players through median (HR: 1.30, 95% CI: 1.13-1.50, p < .05) and trichotomized tertile split (HR: 1.40, 95% CI: 1.18-1.68, p <. 05; tallest 33.3% compared to shortest 33.3%) analyses. The uniqueness of examining the height-longevity hypothesis in this relatively homogeneous sub-population should be considered when interpreting these results. Further understanding of the potential risks of early mortality can help generate discourse regarding potential at-risk cohorts of the athlete population.

Geographical Variations in the Interaction of Relative Age Effects in Youth and Adult Elite Soccer.

Selection biases based on the use of cut-off dates and the timing of athletes' birthdates have been termed relative age effects. These effects have been shown to differentially affect individuals involved in sport. For example, young male soccer players born early in their age group are overrepresented in elite teams while studies in adult soccer indicated potential carry-over effects from talent development systems. This two-study approach focuses on the processes within multi-year age groups in youth and adult elite soccer and on the role of players' age position within the age band with regard to players' birth year and birth month. Study 1 tests for an interaction of two different types of relative age effects among data from participants in the last five Under-17 FIFA World Cups (2007-2015). Analyses revealed a significant global within-year effect and varying birthdate distributions were found between confederations. Even stronger effects were found for constituent year effects. For the total sample, a multi-way frequency analysis (MFA) revealed an interaction with a pattern of a stronger within-year effect for the younger year group. This study highlights the need to consider interactions between different types of age effects. The main aim of Study 2 was to test for carry-over effects from previously found constituent year effects among players participating in the 2014 soccer World Cup and, therefore, to test for long-term effects of age grouping structures used during earlier stages of talent development. A secondary purpose of this study was to replicate findings on the existence of within-year effects and to test whether effects vary between continental confederations. No significant interaction between constituent year and within-year effects was shown by the MFA among the World Cup sample and previous findings on varying within-year effects were replicated. Results indicate that long-term effects of age grouping structures in earlier high-level talent development structures exist.

A Systematic Review of Influences on Development of Athletes With Disabilities.

Compared with mainstream sport athletes, relatively little is known regarding the factors affecting the development of athletes with a disability. Sport-specific training programs are essential to athletes' successful performance; to create appropriate programs and strategies, a clear understanding of the nuances of development of athletes with a disability is important. The objective of this systematic review was to synthesize existing research on development in athletes with a disability and examine the key determinants of successful development and sporting performance. After a search of the Web of Science and SPORTDiscus databases, 21 articles were identified that met the inclusion criteria, which were assessed using the Mixed Methods Appraisal Tool and categorized into 3 groups: training and practice, shortterm interventions, and long-term changes due to training. Among the studies, there was a disproportionate focus on immediate interventions and training programs and less on long-term development. The review reflected a lack of research on sportspecific development of athletes with a disability, which raises concerns regarding the effectiveness and appropriateness of current training practices.

Does Early Career Achievement Lead to Earlier Death? Assessment of the Precocity-Longevity Effect in Professional Basketball Players.

OBJECTIVES: To examine the precocity-longevity (P-L) effect in North American professional basketball players who debuted between 1946 and 1979, and to determine whether playing position and decade of play influenced the relationship between age of career achievements and life span. METHODS: A total of 1852 players were evaluated from a recognized sports archive (i.e., http://sports-reference.com), which provided information on date of birth, death, and career debut, playing position, and indicators of achievement (i.e., All-Star team and/or All-League team selection). Athletes were categorized as above or below the median age of professional debut and median age of selection to first All-Star team and/or All-League team. Analyses of deceased players (n = 598) were comprised of bivariate correlations between age of achievement (age of debut, age of first All-Star game, and age of first All-League team selection) and age of death, and t-tests to compare the average age of death of early and late achievers (p < 0.05). Survival analyses, using the entire sample (living and deceased players), compared the life spans between those who debuted above and below the median age of achievement for each indicator of achievement. RESULTS: Only the correlation between age of professional debut and age of death (r = 0.33, p < 0.001), age of first All-Star game and age of death (r = 0.29, p < 0.05), and the t-test comparing the average death age of early (66.4 years) and later (69.3 years) debut age groups (p = 0.01) reached statistical significance. However, survival analyses demonstrated a trend for lower risk of death for early achievers, with one exception (i.e., age of debut); this trend was not statistically significant. CONCLUSION: Results did not support the P-L hypothesis, suggesting that sample characteristics (i.e., physical fitness of high performance athletes), and measurement methodologies, may influence support for the proposed hypothesis in sport. However, future research would benefit form larger sample sizes and cause of death data.

The relative age effect in sport: a developmental systems model.

The policies that dictate the participation structure of many youth sport systems involve the use of a set selection date (e.g. 31 December), which invariably produces relative age differences between those within the selection year (e.g. 1 January to 31 December). Those born early in the selection year (e.g. January) are relatively older­by as much as 12 months minus 1 day­than those born later in the selection year (e.g. December). Research in the area of sport has identified a number of significant developmental effects associated with such relative age differences. However, a theoretical framework that describes the breadth and complexity of relative age effects (RAEs) in sport does not exist in the literature. This paper reviews and summarizes the existing literature on relative age in sport, and proposes a constraints-based developmental systems model for RAEs in sport.