In a book published in 2019, The Constraints-Led Approach: Principles for Sport Coaching and Practice Design by Renshaw, Davids, Newcombe & Roberts, they purposed degeneracy as the platform for skill adaptation. 

Degeneracy is defined as “the ability of elements that are structurally different to perform the same function or yield the same output”. Think about it as ability of an athlete to effectively perform a movement in a variety of different ways through varying levels of complexity. 

Degeneracy has been demonstrated in studies of football kicking (Chow, Davids, Button, & Koh., 2008) and the basketball hook shot (Rein, Davids, & Button, 2010) demonstrating how individuals used lower and upper body joints and limb segments, respectively, in very different ways to perform successfully, as key task constraints (such as height of a football chip and distance to basket for a shot) were changed.

This means we should seek to provide an environment that provides plenty of chances for athletes to adapt and perform under various conditions, but achieve similar outcomes. Practice should promote variability, both within and across patterns, and push athletes to explore multiple solutions to a given task or problem. 

In the case below, the QBs were to complete a pass to a stationary or moving WR, but they were encouraged to find different and new ways each throw. This is in contrast to how the majority of practice looks for QBs, repeating “perfect” stationary mechanics with little to no variation in tempo, arm angle, foot angles, or pass rusher. Yet in the actual game, the majority of throws involve a QB demonstrating great degeneracy in successful passes.

In the next video, you’ll find another strategy to help athletes explore different ways to successfully solve the task of landing and jumping.

If one views degeneracy as the platform of skill adaptation, then we should be pushing our athletes to search for creative and authentic ways to solve problems. Take off your athlete’s governor and let them go!


Michael Zweifel 

Educational Lead


  1. Chow, J. Y., Davids, K., Button, C., & Koh, M. (2008). Coordination changes in a discrete multi-articular action as a function of practice. Acta psychologica, 127(1), 163-176.
  2. Rein, R., Davids, K., & Button, C. (2010). Adaptive and phase transition behavior in performance of discrete multi-articular actions by degenerate neurobiological systems. Experimental brain research, 201(2), 307-322.
  3. Renshaw, I., Davids, K., Newcombe, D., & Roberts, W. (2019).The constraints-led approach: Principles for sports coaching and practice design. Routledge.