The slice is the shot that lets a player keep going

A backhand chip asks far less of the shoulder than a full drive, and that difference decides careers after thirty.

Players do not drift toward the slice because they suddenly discover its tactical charm at thirty two. They drift toward it because the shoulder stops paying for the alternative.

Look at what a two handed drive actually demands. The arms accelerate a racket through a long arc, and the hard part is not the acceleration, it is the stopping. After contact the shoulder has to decelerate the whole limb through a big range, and it does that with muscles working while lengthening, which is the highest-force way a muscle can operate. Repeat that a thousand times a week and the rotator cuff and the tissue at the back of the shoulder take a beating that accumulates quietly for years.

A slice is a different machine. Shorter backswing, a high-to-low path, contact closer to the body, and much of the racket speed produced by dropping the arm rather than whipping it. Deceleration afterwards is gentler because there is less speed to kill and the arm finishes across the body in a position where the big muscles of the back can help. The shot is not free, mind. It moves cost downward, into the front leg.

That is the trade nobody mentions. To hit a slice that stays low you need to get under the ball, which means a deep bend in the leading knee and a long hold in that position while the racket travels. The load lands on the thigh and on the knee cap tendon, and the deeper and lower the shot, the longer the hold. A player with a sore knee slices badly, and it floats, and it sits up, and the opponent kills it. That is why an aging player who has lost the leg cannot rescue himself with the slice either. The shot has its own rent.

There is also a wrist story. The slice locks the wrist in a stable extended position rather than snapping it through, which is why players with wrist trouble find slicing tolerable when driving is not. Same reason a doubles specialist can play for two decades with a wrist that would never survive a modern topspin backhand.

So my claim is simple. The slice survives in the professional game not because it wins points, though it does, but because it is the only groundstroke whose load can be paid by different tissue than the one that is currently failing. That is a physiological function, not a tactical one, and it explains why coaches who dismiss it as defensive keep watching their players reinvent it at thirty.