Originally Posted by directionals
If the ball is struck at above the equator, then I don't understand why people say hit the ball from 8 o'clock to 2 o'clock. Shouldn't that be 10 o'clock to 2 o'clock then?
If you brush the ball from 10 o’clock to 2 o’clock, angle theta would be around 30 degrees (ϴ
= 30°) and this brush motion creates only horizontal component V
SpinHor, see post #1, fig.3.
Topspin component of the racquet velocity will be zero, V
Topspin = V
SpinVer = 0. With tilted racquet (ϴ
= 30°) and without topspin you definitely hit the ball into net.
There is simple approximate rule: For every degree of closed racquet face you have to swing the racquet the same degree upward. So, topspin component is very important for twist serve.
That’s why you have to swing from 8 o'clock to 2 o'clock. If ϴ
is more 15° you maybe should brush the ball from 7 o'clock to 1 o'clock.