Originally Posted by spacediver
If so, then wouldn't it make sense to have the shoulders and chest square with the net/target before the arm starts to crack? So long as you prevent the torso from overrotating, and "apply the brakes", then that momentum will be channeled into the arm.
Why doesn't serve instruction encourage this delayed cracking of the whip principle between torso and arms?
The instructions do encourage the torso rotation, except that you have the wrong image. The torso is supposed to rotate vertically, aka shoulder roll, not horizontally as in the forehand. As you can imagine if you rotate the torso vertically, then the shoulders will remain sideways. That's why the instructions tell you to make sure that you don't open the shoulders. Of course, the instructions could tell you to rotate the torso vertically, not horizontally, but then, they wouldn't be the complete garbage that they are, no?