Skill acquisition specialist, Mark Upton, helps us navigate the complex mix of variables that every young player experiences throughout their development. The way in which each player perceives these events can lead to very different results – some will be stifled by the experience, while others will go on to become the future superstars of our game.


In the backyard of an Australian home, a young boy tries to chip a football over a small pond and into his mini- goal on the other side. In Brazil, teens playing on a rocky and dusty street show off exquisite first touch skills as the ball reacts in unpredictable ways off the playing surface. In England, a seven-year-old successfully attempts a back-heel pass to a teammate during practice but is told by her coach to ‘stick to the basics’. In Spain, an experienced youth team coach creates a conditioned small-sided game to work on quick transitions with his players. In Germany, kids are fully engaged for hours on end playing a game of football in the local park. And in a youth game in the United States, the bigger, faster and stronger boy dribbles all the way from the half way line into the box and scores.

If you’ve been involved with the development of young players for any period of time you will appreciate that the above examples can all influence their learning. What you may also understand is that it’s a complex mix of these ‘experiences’ that shape the development of a young person and hopefully their future success. This article will explore the theoretical and growing empirical evidence that can help us understand the complexity of each experience and help us create positive player development environments.

Kids in Sudan play on a dirt pitch. Photo: jay-chilli

Kids in Sudan play on a dirt pitch. Photo: jay-chilli

Taking a constraints-led approach to skill development helps us appreciate the complex mix of variables that
can affect the development of skill. In his book ‘Outliers’, Malcolm Gladwell demonstrated that there are a lot more variables involved in an individual’s success than society cares to admit. Our job is to understand these variables in the hope that we can create an environment that maximizes skill development. The coach’s goal is to manipulate the environmental conditions to create a ‘perfect storm’ for player development. To do this we must understand the principles of nonlinearity and constraints.

A Systems Approach

The principles of nonlinearity and constraints come from academic theories – Dynamical Systems Theory (DST) and Complexity Theory (CT) – that have been used to understand weather systems and economic markets as well as motor learning, skill acquisition and talent development in team sports. From a coaching perspective, these theories allow us to view the learner (young player) and learning process (becoming a skilled football player in the technical-tactical and psycho-social sense) as a dynamic and complex system. These theories allow us to better understand how system inputs (training environments) interact to create system outputs (skill).

A perfect storm is a weather system, all be it a powerful, dynamic and complex one. It has formed from seemingly harmless atmospheric conditions that have combined, interacted and evolved to create something with devastating consequences. In the same way, we can think of a player’s development journey as the formation of a weather system.

In the same way, we can think of a player’s development journey as the formation of a weather system.

The principle of constraints, as outlined in the above theories, guides our understanding of the ‘system inputs’ that determine the development of skill or the formation of a perfect storm. The principle of nonlinearity explains that the same inputs don’t produce the same outputs – talent development doesn’t happen in a ‘straight line’; there tend to be peaks, troughs and plateaus and a storm is unpredictable. In other words, timelines and experiences that develop certain skills in one individual may not develop the same skill in another. The principle of nonlinearity recognises that small, seemingly insignificant experiences within a player’s development journey, their system inputs, may be responsible for kick-starting the development of world-class skills, their system outputs.

Take Luis Suarez, who reportedly spent hours and hours playing football barefoot on grass as a young player. This was a system input. Some have suggested his exceptional balance, unique (deceptive) body movements and small bio-mechanically efficient steps – responsible for both his injury resistance and creative behaviour -evolved from this playful environment. This is a great example of a key development experience that fits the theories of nonlinearity & constraints, mentioned above.

Luis Suarez for Barcelona. © Natursports |

Luis Suarez for Barcelona. © Natursports |

When we appreciate that development doesn’t take place in a straight line we can appreciate that playing barefoot on grass will not automatically reproduce another Suarez, as there are countless other system inputs (be they cultural, physical, cognitive, or emotional) that have combined to create the ‘perfect storm’ that is Suarez – the good and the bad. These system inputs are often referred to as constraints, and our goal as coaches is to identify and understand the key constraints in order to allow development to take place.

A player’s behaviours, actions and decisions emerge from the interaction of constraints impinging on their movement system. To go back to the weather metaphor, the ‘perfect storm’ is a result of the interaction of many atmospheric constraints and perturbations – sometimes the flap of a butterfly’s wings is critical in the forming of a storm, yet in most cases the flap has no such effect. Just as time spent playing barefoot on grass may be more beneficial to some players than others, we must recognise therefore that small experiences can create a development ripple that shapes a player’s journey and the development of world class skill.

The examples given at the beginning of this article all constrain the development journey. Sometimes the smallest of things, such as a coach telling a player to ‘stick to the basics’, can significantly impact the outcomes of the developmental journey. In this example, perhaps the player becomes completely lacking in creativity. This is akin to the butterfly effect causing the perfect storm.

Figure 1: Constraints-Led Approach.

Figure 1: Constraints-Led Approach.

Constraints-Led Approach

Karl Newell (1986) is prominently cited for defining three primary categories of constraints which interact to shape coordination and motor control in a developing youngster. These are the: task, person and environment. His framework contradicts the traditional view that development is determined by either nature (genetically encoded ‘natural talent’) or nurture (for instance the mythical and completely false ‘10,000 hour rule’). Newell’s ideas have since been formalised as a Constraints- Led Approach to skill acquisition and player development in the sporting domain. See figure 1 for my version of the framework.

[Newell’s] framework contradicts the traditional view that development is determined by either nature or nurture.

Like any organic process the right conditions are required for growth. Just as gardeners create fertile conditions for flowers to thrive, coaches must create the optimal conditions to maximise skill development for players. Starved of sun and water a flower will wither and die, in the same way players exposed to inappropriate conditions (for example, 11-a-side at too young an age) will loose interest, burn out, or fail to flourish. A constraints led approach to skill acquisition provides a framework to help us understand why certain combinations of conditions or constraints are more likely to reap positive results.

Around the world we have seen a movement towards small-sided games for junior players, why? Is it recognition of the importance of task constraints in skill development? Is it recognition that the size of the area and the ball to player ratio influence the development of skill? Is it recognition of futsal’s influence in developing skilful football players?

Player development is inherently complex, but getting a grasp of this concept is crucial for predicting the impacts that certain constraints can have on developing players. There are no recipes for creating perfect players, nor are there simple solutions to understanding the depth of this topic. Instead, the best way to fully appreciate the power of compounding constraints is to examine the concept in detail and from different angles, and most importantly, learn from applying it in a practical way relative to your own specific context. As coaches involved in player development we need to become skilled at manipulating constraints to shape the development of our players.

Player Development Project Magazine will continue to explore this in future issues.


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Davids K, Button C, Bennett S. (2008) Dynamics of skill acquisition: A constraints-led approach. Champaign, IL: Human Kinetics.

Hornig M, Aust F, Gu?llich A. (2014): Practice and play in the development of German top-level professional football players. European Journal of Sport Science.

Newell, K. M. (1986). Constraints on the development of co-ordination. In M. G. Wade & H. T. A. Whiting (Eds.), Motor development in children: Aspects of co-ordination and control (pp. 341- 360).