Tommy Lundberg
Docent in Physiology, Karolinska Institutet
Recently, some Swedish soccer clubs have attracted attention by introducing more structured/professionalized talent development systems and lowering the age for selection in academies and elite environments. This development has been met with criticism from researchers who have argued that early and structured talent systems can be counterproductive to long-term athletic development. In this article, I intend to summarize the current state of research and highlight the key arguments that explain why researchers are critical.
A fundamental problem in identifying talent is the lack of reliable markers that can predict future success. [1] An obvious problem with early selection is that it amplifies established effects such as the relative age effect and the relative maturity effect. The relative age effect means a skewed distribution in favor of players born early in the year. The relative maturity effect means a skewed distribution in favor of early biological maturity. Boys who reach puberty early have an advantage in terms of body size, strength and physique, [2] which is also noticeable on the pitch. Only 5% of all players in U15 academies in England, for example, are physically late-maturing according to the most established methods of assessing maturity. [3]
The problem is that neither your date of birth nor your maturity timing says anything about your potential to be a successful athlete as an adult. In the end, everyone grows up. We recently looked at who has reached the NHL from Swedish ice hockey high schools in the last 20 years. [4] It turns out that there was a preponderance of players who were later than average in their maturity in their first year of high school. This was despite the fact that there was a significant bias toward early maturity when we looked at tryouts for the first junior national team (Team 16) instead. Similar findings were made in the context of relative age effects in the NHL. Those born in the last quarter score more points on average and have higher salaries than those born in the first quarter. [5]
In their discussion, the researchers pointed out the problematic fact that talent selection usually begins around puberty or even earlier, i.e., at an age when performance in adolescence does not correlate with later performance in adulthood.
The current selection model, in which selection is primarily based on current performance, shows a very weak correlation with the long-term development or future success of senior players. A meta-analysis of more than 13,000 athletes (from 2006 to 2021) found that performance in youth has limited predictive value for later senior success. [6] This observation was robust across different sports, sexes and geographical locations. The correlation became weaker the younger the athlete was at the time of the study. In their discussion, the researchers pointed out the problematic fact that talent selection usually begins around puberty or even earlier, i.e., at an age when performance in adolescence does not correlate with later performance in adulthood.
A systematic review of 29 studies (between 2009 and 2022; 68% of athletes were from team sports) showed an inverse relationship between early entry into structured talent programs and later elite success. [7] Of particular note was that athletes who reached the furthest as adults had entered these structured programs later than athletes who succeeded only as juniors. The researchers therefore concluded that early involvement in these systems is positively correlated with junior performance, but negatively correlated with long-term senior performance.
Another study from 2023 examined the overlap between athletes who are successful as juniors and seniors. [8] It was found that:
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- 89% of successful junior athletes (U17/U18) do not reach international senior level
- 82% of internationally successful senior athletes had no equivalent success at junior age U17/U18
- Only 7% of successful junior and senior athletes overlap at international level.
The researchers stated that the findings challenge the notion of sporting talent and expertise as well as the prevailing selection methods and talent development programs.
A German study examined the difference between female soccer players who have reached the international level (national team) and the national elite (Bundesliga).[9] By the age of 18, the national team players had completed less soccer training overall, but more peer-led soccer training and coach-led training in other sports than those who had only reached the national league.
A review from 2022 examined what predicts the success of juniors compared to seniors. [10] The compilation included a total of 71 different studies with over 9000 athletes, 67% of which were from more complex sports referred to as “game sports” (e.g. basketball, soccer and tennis).
It was found that world-class athletes at senior level are characterized by:
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- More diversified sporting activity during childhood
- Later specialization in the main sports
- Less sport-specific training at a young age
- Slower initial progression rate
This was in contrast to successful junior athletes, who more often show early specialization and extensive sport-specific training. The researchers discussed that overly specialized training in childhood can inhibit long-term development by, for example, increasing the risk of overuse injuries, athletic burnout and poor matching between the individual athlete and their sport, as well as limiting the positive effects of training in the long term.
Another, very similar study, which included data from 51 international studies (57% of the athletes were from team sports), came to the same conclusion:[11] adult world-class athletes devoted more time to multisport training in childhood, started their main sport later, trained less in the main sports and initially made slower progress than athletes who reached national but not international class.
A particularly significant research study was initiated by UK Sports, which asked the world’s leading researchers in the field to compile the state of knowledge on what is needed to develop sporting excellence at international level. [12] The study, which reviewed hundreds of original studies, led to several conclusions:
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- Genetic factors can influence the development of athletic potential – but there are no genetic markers that can be used to predict future performance. This underlines the importance of keeping all potential genetic talent in the system for as long as possible.
Super-elite athletes also exhibit specific psychological traits:
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- Conscientiousness
- Optimism
- Hopefulness
- Perfectionism
In terms of contextual factors, it was found that small and medium-sized communities often provide the most favorable conditions for development. Supportive families, coaches and networks are also important and characterize those who reach the highest level. It also became clear that early success is a poor indicator of later excellence.
It is time to ask how it is that a multi-sport background is so closely linked to later success. One plausible but unexplored explanation is that those who have a high genetic potential for sport naturally want to try many different sports. However, several studies specifically point to the link between multisport and the ability to learn and develop in a later phase of adolescence, which is very interesting from a talent development perspective.
The motto of “as many as possible for as long as possible” during childhood seems to be the approach that leads to optimal use of resources while having the potential to promote both long-term development and future world-class performance.
A study of 100 youth soccer players (average age 12) evaluated by 14 coaches showed that: [13]
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- Better learning correlated positively with prior multisport involvement
- There was no correlation between learning and the amount of previous soccer-specific training
The results thus indicate a delayed but positive effect of an early multisport background on later soccer development.
A longitudinal study [14] of German youth players aged 11-13, based on video analysis of 5v5 games, showed that players with strong development in match play over 24 months had a more extensive:
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- Non-organized soccer play
- Organized training in other sports besides the main sport
The amount of organized soccer training showed no correlation with the rate of development.
An analysis of experts versus non-experts [15] (based on decision making in soccer) revealed the following:
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- Experts have completed more sport-specific training from the age of 12
- Approximately 4000 hours of concentrated sport-specific training over a 13-year period was required to reach the level of an expert
- A negative correlation was found between the number of previous sporting activities and the amount of training needed to reach expert level
- The more previous sporting activities, the less time was needed to reach international standards
These results also support the motto of enabling broad sports participation at a young age, not forcing early specialization, valuing varied and less organized spontaneous sports and creating a developmental environment that supports long-term development.
Structured talent systems and/or early specialization at a young age also have potential risks that have been highlighted in research (although not all of them are fully documented):
Based on the current state of research, it is therefore generally recommended to prioritize a broad participant base over a longer period of time (as many as possible, for as long as possible) and the promotion and facilitation of multisport in childhood and early adolescence. There should therefore be flexible development pathways that allow for later development and later entry into more structured programs in an elite environment. It is clear that systems that provide for early selection and lots of training in the main sport do not attract those with the greatest genetic potential to go far in that sport. Instead, the athletes who go furthest tend to try several different sports in childhood and often show slower initial progress. If we organize away the opportunity to get to the elite level later in life, at an age when better quality and quantity structured training is really needed, this is likely to lead to a poorer quality of the elite players we produce.
One problem in the current structure of elite player paths, which is on the verge of over-organization, is that a kind of perceived contradiction has arisen between the wider sport participation and elite development pathways. However, in line with what has been outlined in this article, broad participation is a prerequisite for creating world-class athletes. And the elite creates interest, economic incentives, and role models that encourage broad participation. The two directions, broad participation and elite pathways, should therefore be able to coexist without problems and need not be played off against each other.
In order to get as many people as possible involved and stay in sport, we also need to listen to the children themselves. Children and young people report that they play sport because they enjoy it and that they stop playing sport when they no longer enjoy it. The key drivers for why they play sport and why it is perceived as fun align well with recognized motivational factors: [20] feeling competent and developing/learning, feeling a sense of belonging and a sense of autonomy and self-determination, as well as positive coaching and leadership. These factors apply regardless of age and level of ambition in adolescence. Again, there is no reason to pit the wider participation and the elite against each other.
Finally, of course, I should return to the article’s original question of why researchers are so skeptical of early and structured talent development systems in sport. The answer is that, to the best of our knowledge, they are not necessary, perhaps even counterproductive, to producing world-class athletes in our biggest and most popular ball sports. They bring few obvious advantages, but a number of potential disadvantages. The motto of “as many as possible for as long as possible” during childhood seems to be the approach that leads to optimal use of resources while having the potential to promote both long-term development and future world-class performance. Of course, if our future stars are to make it to the top, they will eventually need to be involved in a more structured and resource-intensive environment with lots of high-quality training. But there is not much to suggest that this needs to happen in childhood.
Copyright @ Tommy Lundberg 2024
[1] Johnston K, Wattie N, Schorer J, Baker J. Talent Identification in Sport: A Systematic Review. Sports Med Auckl NZ. 2018 Jan;48(1):97–109.
[2] Malina RM, Eisenmann JC, Cumming SP, Ribeiro B, Aroso J. Maturity-associated variation in the growth and functional capacities of youth football (soccer) players 13-15 years. Eur J Appl Physiol. 2004.
[3] Johnson A, Farooq A, Whiteley R. Skeletal maturation status is more strongly associated with academy selection than birth quarter. Sci Med Footb. 2017.
[4] Niklasson E, Lindholm O, Rietz M, Lind J, Johnson D, Lundberg TR. Who Reaches the NHL? A 20-Year Retrospective Analysis of Junior and Adult Ice Hockey Success in Relation to Biological Maturation in Male Swedish Players. Sports Med Auckl NZ. 2024 May;54(5):1317–26.
[5] Fumarco L, Gibbs BG, Jarvis JA, Rossi G. The relative age effect reversal among the National Hockey League elite. PloS One. 2017;12(8):e0182827.
[6] Barth M, Güllich A, Macnamara BN, Hambrick DZ. Quantifying the Extent to Which Junior Performance Predicts Senior Performance in Olympic Sports: A Systematic Review and Meta-analysis. Sports Med Auckl NZ. 2024 Jan;54(1):95–104.
[7] Güllich A, Barth M. Effects of Early Talent Promotion on Junior and Senior Performance: A Systematic Review and Meta-Analysis. Sports Med Auckl NZ. 2024 Mar;54(3):697–710.
[8] Güllich A, Barth M, Macnamara BN, Hambrick DZ. Quantifying the Extent to Which Successful Juniors and Successful Seniors are Two Disparate Populations. Sports Med Auckl NZ (2023) 53:1201–1217.
[9] Güllich A. “Macro-structure” of developmental participation histories and “micro-structure” of practice of German female world-class and national-class football players. J Sports Sci. 2019 Jun;37(12):1347–55.
[10] Predictors of Junior Versus Senior Elite Performance are Opposite: A Systematic Review and Meta-Analysis of Participation Patterns – PubMed [Internet]. [cited 2024 Nov 13]. Available from: https://pubmed.ncbi.nlm.nih.gov/35038142/.
[11] Güllich A, Macnamara BN, Hambrick DZ. What Makes a Champion? Early Multidisciplinary Practice, Not Early Specialization, Predicts World-Class Performance. Perspect Psychol Sci J Assoc Psychol Sci. 2022 Jan;17(1):6–29.
[12] Rees T, Hardy L, Güllich A, Abernethy B, Côté J, Woodman T, et al. The Great British Medalists Project: A Review of Current Knowledge on the Development of the World’s Best Sporting Talent. Sports Med Auckl NZ. 2016 Aug;46(8):1041–58.
[13] Coach-assessed skill learning progress of youth soccer players correlates with earlier childhood practice in other sports – Arne Güllich, Robin Cronauer, Johannes Diehl, Luca Gard, Christopher Miller, 2020 [Internet]. [cited 2024 Nov 13]. Available from: https://journals.sagepub.com/doi/full/10.1177/1747954120912351
[14] Güllich A, Kovar P, Zart S, Reimann A. Sport activities differentiating match-play improvement in elite youth footballers – a 2-year longitudinal study. J Sports Sci. 2017 Feb;35(3):207–15.
[15] Baker J, Côté J, Abernethy B. Sport-Specific Practice and the Development of Expert Decision-Making in Team Ball Sports. J Appl Sport Psychol. 2003 Jan 1;15(1):12–25.
[16] DiFiori JP, Benjamin HJ, Brenner JS, Gregory A, Jayanthi N, Landry GL, et al. Overuse injuries and burnout in youth sports: a position statement from the American Medical Society for Sports Medicine. Br J Sports Med. 2014 Feb 1;48(4):287–8; Vaughan J, Mallett CJ, Potrac P, Woods C, O’Sullivan M, Davids K. Social and Cultural Constraints on Football Player Development in Stockholm: Influencing Skill, Learning, and Wellbeing. Front Sports Act Living. 2022;4:832111.
[17] Puzzitiello RN, Rizzo CF, Garvey KD, Matzkin EG, Salzler MJ. Early sports specialisation and the incidence of lower extremity injuries in youth athletes: current concepts. J ISAKOS Jt Disord Orthop Sports Med. 2021 Nov;6(6):339–43.
[18] Full article: ‘You’ve not made the grade, son’: de‐selection and identity disruption in elite level youth football [Internet]. [cited 2024 Nov 13]. Available from: https://www.tandfonline.com/doi/full/10.1080/14660970802601613.
[19] Mosher A, Till K, Fraser-Thomas J, Baker J. Revisiting Early Sport Specialization: What’s the Problem? Sports Health. 2021 Oct 15;14(1):13.
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