I have a tennis partner who has this shot that (I think it is a slice?) looks like it has backspin on it. When the ball hits the ground after the bounce, it basically just almost stops forward progress and has a "tumbling" action. Is that what a pro ATP slice is supposed to be like? If not, what does a pro ATP sliced ball do after the first bounce? (if the returner does not return the ball). In other words, what kind of action is on the ball?