Time your exit

Like many things in life, timing is everything. What is the optimal timing of foot placement with respect to time of shuttle impact in singles? Consider the case of striking the shuttle when the shuttle is far from the centre of the court, without a scissor jump, and it is not a winning shot. The player must coordinate the actions of placing the racket foot on the floor, striking the shuttle and stepping back towards the centre of play.
The basic choice is whether to place the racket foot on the floor before or after hitting the shuttle; both are observable.
Consider that the player steps first and then hits the shuttle. That means that the player is, in effect, waiting for the shuttle to arrive at the point of contact. What could we say about this scenario? Let's assume that the player is in the right place and in good time. Now imagine the player has played the shot, and would like to move to get ready to hit the next shot. How could the player best prepare to move into position? Would it be better to do a little jump to pre-load beforehand to increase the explosiveness?
Typically it would require a lot of energy to arrive before the shuttle. It would also introduce an extra movement before the player would be ready to move to hit the next shuttle.
Now imagine that the player lands sometime after hitting the shuttle. If the landing is significantly after the point of impact, the player will be under pressure to recover for the next shot. Consider the recovery step. What is the best way to maximise this step? It's best to be quick and explosive and if it had a pre-load it would be great. It should be quick and explosive, just like a normal split step. But we can say that it is performed with the certainty that the movement following will be in a particular direction; the movement will be back towards the centre of play. So, we could say that the lunging step should ideally be the pre-loading movement for the recovery step. Recall Hill's equation, which was posted previously. This gives us a shape for the step and some information about how the leg should be bent. On a more basic level, we can say that the lunge should be performed with a certain degree of momentum that allows the player to reach the shuttle, but does not overburden the player in making the recovery step.
So, to recap all that stuff, the movement to the shuttle should ideally be in preparation for the movement away from the shuttle. As Kenneth might say, wow.
What might the implications of that be? Well, we can say that if we haven't placed the racket foot on the floor, we can use the backward leg for control of the positioning. We can say that we avoid the situation where we have to alter the bend of the front leg in order to adjust the position. This gives us a chance to make the push back as effective as possible.
...consider your exit strategy carefully. Here's a little video to stimulate some thought..