The return position is a statement made before the ball is struck

Time against angle

A returner standing well behind the baseline gives himself more time to see and reach the serve, which is why it is the instinctive response to genuine pace. The cost is that a wide serve pulls him further off the court, since the extra distance he stands back multiplies the lateral distance he must cover. Standing close to the baseline reverses the trade, cutting the angle sharply but leaving almost no time to react to a fast serve into the body.

Neither position is correct in the abstract, and the choice depends on the server's pace, his preferred targets and the surface underfoot. What makes it a craft rather than a preference is that the position can be changed between points and even between first and second serves.

What the server sees

The returner's position is visible before the toss, and every competent server uses it to select the serve he is about to hit. A returner standing deep is inviting a serve into the body or a short wide one that dies before he can reach it, because he has surrendered the angles. A returner crowding the baseline is inviting a heavy serve at his hip, since he has no time to move his feet and create space to swing.

This is why an unchanging return position is exploitable: the server acquires a reliable read and spends the match hitting the serve it concedes. The counter is to vary the position, which forces the server to make his selection later and with less confidence in what he will find.

The split step and the first movement

Whatever position the returner takes, the split step has to land as the server makes contact, because it is what converts a standing body into a moving one. Landing too early means the legs have already absorbed and released, leaving the returner flat-footed at the moment he needs to push off. Landing too late means he is still in the air when the ball is travelling, and the first step is taken from a body that has no ground contact.

The first movement itself is usually a small step across rather than a lunge, because the direction of the serve is often still uncertain. Returners who lunge on the first step are committing to a read, and against a server with a disguised toss that is an expensive habit.

The second serve is a different problem

A second serve arrives slower and with more spin, which means the returner can move forward and take it earlier without being rushed. Stepping in shortens the court for the server and takes away the kick before it climbs above the returner's shoulder. It also applies pressure, because a server who sees the returner advancing knows that a conservative second serve will be attacked.

The risk is that the server responds by hitting a genuinely aggressive second serve, and a returner standing close has no time for it. The negotiation between those two possibilities is one of the most consistently interesting exchanges in a match and it happens entirely before contact.

Returning as position rather than as a shot

A return that lands deep and near the middle is often more valuable than a winner attempt, because it denies the server an easy first ball. The server's advantage on his own serve comes largely from the short reply that lets him step in and dictate with his next shot. Taking that away converts the point into a neutral rally, which is where the returner's own patterns become relevant again.

Returners who chase winners from every ball convert a small number of points and hand over many more through errors that end the point immediately. The discipline is to distinguish between the serve that can be attacked and the one that can only be neutralised, and to make that judgement quickly.