For those unfamiliar, 24th century tennis was introduced in TNG's Suddenly Human, then brought back in Rivals in DS9.
It's kind of like squash, only with a bunch of angled walls, and balls are only allowed to hit the wall on small circular areas.
That means, if it hits a wall, bounces off another wall, and the second wall hit misses a small circular target, you lose the point.
You would pretty much have to be an expert in the game just to run a single successful rally. Below the pro level, any game would mostly be about both players aiming for the large target on the back wall, and a lot of points would end with a player intentionally letting the ball pass by him and hit the wrong part of another wall, since it happens in a rather small room.
So is tennis in the 24th century an elite, exclusive sport? Or is the idea mankind has just 'evolved' the superhuman fine motor control to hit tiny targets with ease?