Dan catches up with one of the leading lights of ecological dynamics, Rob Gray.Rob is professor of Human Systems Engineering at Arizona State University. In the coaching world, he is better known for the Perception and Action podcast.I ask Rob to give us a basic guide to what is meant by ecological dynamics and perception-action coupling in a sporting context. It includes an outline of how the constraints-led approach gives the players opportunities to develop.The discussion moves around the following topics:How does our training sessions need to adjust?What are we doing already which is probably effective, though we didn't know?How do we coach areas of the game which need players to have a safe understanding of the movements involved?How would you coach place-kicking and how do we add pressure effectively.In a team context, how does a constraints-led approach work?How close to the real game do we need to get, and conversely, how far away can we get too?To find out more about Rob's extensive work and research go to perceptionaction.com