Originally Posted by rkelley
Respectfully, closing the racquet face at contact with no other changes means that you'll just hit the ball into the net. Closing the racquet face in and of itself does not produce topspin. The racquet has to have a component of its velocity going up to produce topspin.[...]
if he dumps it into the net after tilting the racquet forward, as he mostly likely will do, then he will adjust his swing path accordingly to get it over the net next time by swinging low to high slightly. The key is to have an closed racquet face (i.e. tilted forward, not much, only about 10-15 degrees or so, maybe even a bit less). If the racquet face is not tiled forwards at contact, the spin won't be as intense not matter how steeply you hit upwards and will likely come by sacrificing depth.
That's why you hear coaches sometimes say to lead with the edge of teh racquet. It's a cue to ensure that it is tilted properly.