It is the second serve that wrecks shoulders, not the first

The kick delivery loads the joint in its worst position, and players hit far more of them than the highlight reel suggests.

Ask where a server's shoulder damage comes from and most people will point at the flat first serve, because it is the violent one, the one that makes a noise. I think that is backwards. The first serve is fast, but it is also struck in the position the shoulder is happiest in, with the arm extended high and the racket travelling more or less along the line the arm wants to move.

The kick second serve is not that at all. To make a ball bounce up and away, the racket has to travel across the back of it from low left to high right, which means the arm has to be internally rotated and abducted and then decelerated with the forearm pronating hard against the direction of travel. That deceleration is the injury. The muscles at the back of the shoulder are being asked to catch a limb that is moving fast in an awkward plane, over and over, and unlike the first serve there is no version of the shot that lets the player back off, because a slow kick serve is a point given away.

Then look at how many of them get hit. A player who lands sixty per cent of first serves is hitting a second on four points in ten, and on the second serve he cannot afford to miss, so every one is at full commitment. Across a five-set match and a fortnight of them, the volume is not close.

This is why I am suspicious of the standard prescription for a struggling server, which is to work on the second serve until it is a weapon. Fine in principle. In practice it means adding load to the single most damaging motion in the sport and calling it development.

There is a defensible alternative that has gone out of fashion, which is the flatter, slower second serve aimed at a corner with slice rather than topspin. It is more of a risk on any given point. It is far kinder on the joint, and a player who mixes it in a couple of times a game also stops the returner camping on a predictable kick.

Coaches will tell you the mixed approach costs points. It does.

It also costs fewer months.