Originally Posted by sureshs
The particular way is the intuition of the pros. Just like it is meaningless to ask how Nadal produces a curved trajectory of the ball thinking that he uses mathematics for it.
As far as hitting 5 balls in a row, OK that may not be 5, it may be say 3.
Here is a simple calculation. TW University uses a racket tip speed at impact of 80 mph for ATP forehands. You can do a calculation of how much the tip will travel in a 4 ms dwell time, and it comes out to be 5.7 inches, or 2.2 ball diameters. Add in the fact that for a little more time the racquet will be maintaining its inertia after the ball leaves, and 3 balls in a row is not unimaginable.
Does it mean that the pro guides his racket in a straight line towards the target? No. It just means that he makes solid contact towards the intended direction as part of his up, forward and leftward trajectory of the swing.
I have said many times that topspin cannot be produced by purely rigid bodies. There has to be deformation in a certain dwell time. If you meet the ball in a certain way, it will be deformed and released in such a way that it will have both forward momentum and spin. If you don't meet it solidly, it won't have much pace but will have spin from a grazing motion. The solid meeting is what is commonly called hitting through the ball, and also produces the "pro sound" on impact. The reason it is emphasized is that club players often hit tentatively.
It looks like you cannot describe proper procedure about hitting through, because nobody can express that doesnít exist. Instead you started using one of the vaguest terms as intuition.
To hit the ball solidly we have to increase normal component of the racquet speed relatively to tangential one, because the ball is absolutely symmetrical about its center. The bigger normal component the more solid contact will be.
Have you ever seen billiard pros game? They can create any spin with rigid bodies/balls. But, Iím not talking about pure rigid body, because it doesnít exist.