My advice on guessing is pretty much the same for all shots, except maybe an easy overhead coming at you ... and that is DON'T! If you guess wrong the result is obvious. If you guess "right" there's a good chance you won't be where you want to be anyway ... as in overrunning the ball. Best to be on balance so you can turn to either side quickly and wait until you know where the ball is going before you respond. In reality you have a lot more time than you might think or feel you do.
This is very important during tight volley exchanges at the net like in doubles. I feed balls to my students from the service line and they are always slower and less effective on volleys when they guess than when they don't. I think the same is true for returning serves.
I agree and thinking guessing also has many negative effects, often making
an avg shot great.
MTM Instructor -Pro Supex Big Ace