Announcement

**uspta146749877** · 03-21-2009, 07:01 AM

a bit hard to read

----> your post
Hitting Up On The Serve

--------------------------------------------------------------------------------

got into a disscussion with a friend that even on flat serves you have to hit up on the serve to get it into the box unless your contact point is 12 ft or so above the grond meaning you would have to be 9 ft tall or something like that. does anyone have the link to the picture of the line from contact to the service box which shows the height and geometry. anything else i can do to support my position would be appreciated. my friend is 6'4 and beleives he hits down on his flat serve. he also doe not have much spin on his flat serve will show him johns work to disprove that.
----> my response
Hi,
your post is a bit difficult to read,especially a first sentence.
Ant chance to edit a bit?

**johnyandell** · 03-21-2009, 10:23 AM

I cannot prove this quantitatively but do believe the racket tip is rising all the way until contact. BUT one thing we did see in our trajectory studies was that the ball actuallly leaves the strings on a slight downward path. That is because the angle of the racket face is tilted slightly forward--actually this is the forward angle of the entire arm. In terms of a feeling it's all up--just my opinion.

**llll** · 03-21-2009, 10:44 AM

Originally posted by uspta146749877 View Post

----> your post
Hitting Up On The Serve

--------------------------------------------------------------------------------

got into a disscussion with a friend that even on flat serves you have to hit up on the serve to get it into the box unless your contact point is 12 ft or so above the grond meaning you would have to be 9 ft tall or something like that. does anyone have the link to the picture of the line from contact to the service box which shows the height and geometry. anything else i can do to support my position would be appreciated. my friend is 6'4 and beleives he hits down on his flat serve. he also doe not have much spin on his flat serve will show him johns work to disprove that.
----> my response
Hi,
your post is a bit difficult to read,especially a first sentence.
Ant chance to edit a bit?

put another way when you hit a flat serve are you hitting down or up on the ball. if up (and the spin brings it down since all serves have some spin) can you help me prove that point

**llll** · 03-21-2009, 10:47 AM

Originally posted by johnyandell View Post

I cannot prove this quantitatively but do believe the racket tip is rising all the way until contact. BUT one thing we did see in our trajectory studies was that the ball actuallly leaves the strings on a slight downward path. That is because the angle of the racket face is tilted slightly forward--actually this is the forward angle of the entire arm. In terms of a feeling it's all up--just my opinion.

if you took a straight line from the contact point and the angle downward trajectory woiuld the ball land in the service box? or does gravity and spin bring it into the service box?

**uspta146749877** · 03-21-2009, 12:32 PM

Plagenhoef's Fundamentals of Tennis...

Originally posted by llll View Post

if you took a straight line from the contact point and the angle downward trajectory woiuld the ball land in the service box? or does gravity and spin bring it into the service box?

You may ask whether

404 Not Found

http://tt.tennis-warehouse.com/showthread.php?t=251224

is a correct or partial answer to your question
or whether it provides some constraints how you can serve to get
a ball in.
Your question is a combination of :
a) a feasibilty question in terms of geometry/physics
b) a question about techniques used by high performance players
which is really a question about mechanics/i.e how to do it

John answered the the question b above

By the a speed number 102 miles per hour suggested by

404 Not Found

http://tt.tennis-warehouse.com/showthread.php?t=251224

looks a bit low as well