Question:
Is a good slice supposed to also be deep?
B/c the other day I was having minor problems with short slices on clay, but the answer was to step into the court/be prepare to take off the moment the opponent was fixing to hit a BH (b/c he'd slice most of them).
"Good" comes in many forms.
Deep is good because it gives you more time to close, forces your opponent back so the distance between him and you is larger so you have more time to react, it might lessen the power of his shot as he's leaning back, etc.
But short is also good because he may not be good at hitting passers while moving forward. Also, his contact point will also likely be lower, which means he has to hit up, giving you the opportunity to volley down.
Angle is good because now he has to move forward and laterally.
I was answering from the standpoint of approaching the net but you could make much the same arguments if you stayed back.