Janet L. Starkes

The roles of talent, physical precocity and practice in the development of soccer expertise

Here we consider the potential contributions of talent, physical precocity and deliberate practice in the development of soccer expertise. After presenting a working definition of ‘talent, we examine how coaches perceive and select potential talent. Our findings suggest that much of what coaches see as early talent may be explained by physical precocity associated with a relative age advantage. Finally, as a test of the model of Deliberate Practice, we review the results of studies that assessed the progress of international, national and provincial players based on accumulated practice, amount of practice per week and relative importance and demands of various practice and everyday activities. A positive linear relationship was found between accumulated individual plus team practice and skill. Various practical suggestions can be made to improve talent detection and selection and to optimize career practice patterns in soccer.

A multidimensional approach to skilled perception and performance in sport

SUMMARY Three experiments examined the relative importance of attributes determined largely by the eAciency of the visual/central nervous system versus cognitive domain-specific skills, in the determination of expertise in soccer. In Experiment 1, expert and intermediate soccer players were assessed on various non-specific abilities including: processing (simple reaction time, peripheral reaction time, visual correction time), optometric (static, dynamic and mesopic acuity), and perimetric parameters (horizontal and vertical peripheral range). In Experiment 2, domain-specific variables were assessed including complex decision speed and accuracy, number of visual fixations, fixation duration, and fixation location in solving game problems. Stimuli were initially presented by slides (Experiment 2) and later by 16 mm film (Experiment 3). Eye movements were recorded and analysed. A stepwise discriminant analysis of both non-specific abilities and soccer-specific skills revealed an average squared canonical correlationa 0.84, with the significant step variables all being domain-specific skills. Copyright # 1999 John Wiley & Sons, Ltd.

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.

The road to excellence: deliberate practice and the development of expertise

The relative contribution of domain‐specific and non‐domain‐specific activities to the development of soccer expertise was examined using a retrospective cross‐sectional design. Elite and sub‐elite players aged between 9 and 18 years of age completed a participation history questionnaire under supervision. Weekly and accumulated hours spent in soccer team practice most consistently discriminated between skill levels across age cohorts. Elite players spent more time in decision‐making activities during team practice, possessed higher levels of motivation and had greater parental support. Maturational indices, time spent in playful activities, sporting diversity and time at which specialization occurred did not differentiate between groups. Engaging in activities deliberately designed to improve performance rather than mere experience within the domain or experience of related activities is likely to lead to elite status.

Can We Hasten Expertise by Video Simulations

The potential for training perception and cognition in sport through video simulation of game situations is discussed. Perceptual training studies are reviewed and data from two studies involving slide and video training in basketball are presented. Although video training may enhance the accuracy and speed of decision processes, difficulties arise when the trained processes are assessed by on-courst transfer tasks. Issues that arise in the creation of simulations and assessment of transfer are discussed, and future directions for research are proposed.

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.

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 activitys 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.

Coupling of Eye, Finger, Elbow, and Shoulder Movements During Manual Aiming

Abstract Temporal and spatial coupling of point of gaze (PG) and movements of the finger, elbow, and shoulder during a speeded aiming task were examined. Ten participants completed 40-cm aiming movements with the right arm, in a situation that allowed free movement of the eyes, head, arm, and trunk. On the majority of trials, a large initial saccade undershot the target slightly, and 1 or more smaller corrective saccades brought the eyes to the target position. The finger, elbow, and shoulder exhibited a similar pattern of undershooting their final positions, followed by small corrective movements. Eye movements usually preceded limb movements, and the eyes always arrived at the target well in advance of the finger. There was a clear temporal coupling between primary saccade completion and peak acceleration of the finger, elbow, and shoulder. The initiation of limb-segment movement usually occurred in a proximal-to-distal pattern. Increased variability in elbow and shoulder position as the movement progressed may have served to reduce variability in finger position. The spatial-temporal coupling of PG with the 3 limb segments was optimal for the pick up of visual information about the position of the finger and the target late in the movement.

The Attention Demands of Movements

The probe technique has been employed extensively to measure the attention demands of movement control. Inherent in any RT paradigm is the potential confounding effect of anticipation. Experiment 1 studied this problem by varying probe frequency (or, conversely, catch-trial frequency) for three independent groups of subjects performing the same movement. Probe frequencies of one-third and two-thirds produced V-shaped curves of probe RT plotted against probe position within the movement, while a three-thirds condition was described by a negatively sloped linear function. Because of the different shaped curves it was recommended that a two-thirds frequency be adopted by all researchers in this area. Experiments 2 and 3 looked at the effects of movement length and movement time on the attention demands of movement. Shorter (11-cm) movements were more attention demanding in the middle of the movement than the longer (50-cm) movements, but movement time had no effect.

Temporal and spatial coupling of point of gaze and hand movements in aiming.

Temporal and spatial coordination of both point of gaze (PG) and hand kinematics in a speeded aiming task toward an eccentrically positioned visual target were examined with the Optotrak 3D movement analysis system in tandem with the ASL head-mounted eye tracker. Subjects (N = 10) moved eyes, head, hand, and trunk freely. On the majority of trials, the PG pattern was a large initial saccade that undershot the target slightly, then 1 or more smaller corrective saccades to reach the target. The hand exhibited a similar pattern of first undershooting the target and then making small corrective movements. Previously (W. F. Helsen, J. L. Starkes, & M. J. Buekers, 1997), the ratio of PG and total hand response time (50%) was found to be an invariant feature of the movement. In line with those results, a striking temporal coupling was found between completion of the primary eye saccade and time to peak acceleration for the limb. Spatially, peak hand velocity coincided with completion of 50% of total movement distance. Those findings support a 2-component model of limb control.