# confused w/ the term "MTM"

Discussion in 'Tennis Tips/Instruction' started by mr_fro2000, Sep 28, 2012.

Not open for further replies.
1. ### sureshsBionic Poster

Joined:
Oct 1, 2005
Messages:
40,498
I don't think they can. All they seem to do is to manage to get the racket face perpendicular to the ball trajectory at impact and control the curvature to some extent, so as to meet the trajectory smoothly (as I had said before). You seem to think of linear as parallel to the sidelines. I think of it more as a measure of local curvature of the arc at impact (what you would know as reciprocal of the second derivative).

2. ### 5263G.O.A.T.

Joined:
Mar 31, 2008
Messages:
10,909
I think you are making some very good points here. Even if there are math terms
that account for the arc motions of the body in a linear result, that still does
not change that the actual motion was an arc.

3. ### bhupaesProfessional

Joined:
Aug 8, 2007
Messages:
957
Agree with 5263, this is a good post, toly. And don't write off the picture sequence of Serena you posted above as being all flat and having no topspin. It is not evident from the picture, but her hand is pulling in, causing the racquet to whip into the ball, and it definitely has an upwards movement (can't anything tell about sidespin, though). That plus the forward tilt of the racquet will ensure there is a lot of topspin, probably much more than I can hit! But the trajectory of the ball looks like it will be flat.

Thanks for posting this great pic.

4. ### tolyHall of Fame

Joined:
Sep 2, 2010
Messages:
1,993
It is absolutely obvious that in order to hit through 5 bolls the racquet should move along a straight line at least 10’’ with stable racquet face orientation. “Piston stroke” can provide this, but you don’t want to utilize it because it is slow motion. Then, you should think about approximation of the straight line.

Radius of Osculating circle of the straight line is infinity. Thus, if you use rotational motion only, you have to increase radius of rotation as much as possible. From this point of view, straight arm FH is probably the best, because that creates maximum radius. However, most pros use bend elbow FH. So, they don’t care about hitting through.

If you know some different but particular way to “control the curvature to some extent, so as to meet the trajectory smoothly”, just let me know please.

Last edited: Oct 18, 2012
5. ### tolyHall of Fame

Joined:
Sep 2, 2010
Messages:
1,993

Serena uses very actively ISR before and during impact, but smoothly. I don’t see any abrupt sideways acceleration and it is practically impossible. She really pulls in because ISR stands for Internal Shoulder Rotation.

Last edited: Oct 15, 2012
6. ### bhupaesProfessional

Joined:
Aug 8, 2007
Messages:
957
I think Serena uses a combination of ISR and biceps, pretty late in the stroke (close to contact), hence one might say it's abrupt. But that doesn't really matter. In answer to your question on how to create a linear stroke, notice how the path of the racquet head is pretty much linear for most of the stroke. It becomes circular close to contact due to her ISR and biceps action. Now ask yourself, if the ideal stroke is totally linear, why should Serena change a good thing (linear motion) into a bad thing (motion in an arc), and so close to contact at that? Could it be because the act of pulling in the racquet increases RHS both forwards and upwards?!

7. ### arche3Banned

Joined:
Aug 29, 2009
Messages:
5,387
I think Serena and other pros pull the bicep and use internal rotation of the shoulders to whip the head of the racket at contact. It seems a normal part of the modern type stroke. If you watch old era guys with wood rackets they don't really do this. Its like the serve really. In the serve you serve up so the hand will slow down as the racket whips through the serve. The conti grip and pronation on serve allows this. The fh now follows similar principles of the whip applied in a different way.

8. ### bhupaesProfessional

Joined:
Aug 8, 2007
Messages:
957
Agreed. I haven't studied the pros who wielded wooden racquets much... but I am sure some were very modern - like Bjorn Borg, for instance!

9. ### bhupaesProfessional

Joined:
Aug 8, 2007
Messages:
957
Also, note that it's not all about power - the goal is not to send the tennis ball after the Mars Rover! IMO, tennis strokes have evolved in such a way so as to enable the player to increase pace and control proportionally. The pulling in motion which incorporates both "up" and "across" increases linear pace as well as spin control, as it should.

10. ### arche3Banned

Joined:
Aug 29, 2009
Messages:
5,387
Yeah I saw old videos of Borg hitting the Nada fh.

11. ### LeeDBionic Poster

Joined:
Dec 28, 2008
Messages:
42,444
Location:
East side of San Francisco Bay
I"m pretty sure EllworthVines used a modern forehand from waist up, not using nearly as much legs. His finishes were well past his left shoulder.

12. ### sureshsBionic Poster

Joined:
Oct 1, 2005
Messages:
40,498
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.

13. ### tolyHall of Fame

Joined:
Sep 2, 2010
Messages:
1,993
I think that Serena doesn’t use right arm bicep significantly, because she doesn’t bend additionally her elbow around and after impact. See picture below.

About straight linear motion: She applies bend elbow FH technique, because she can use ISR, the fastest motion of the arm, to build translational motion of the ball. In case of straight arm ISR can create spin and practically zero translational speed. That’s why almost all WTA players use bend elbow FH.

Last edited: Oct 15, 2012
14. ### tolyHall of Fame

Joined:
Sep 2, 2010
Messages:
1,993
It looks like you cannot describe proper procedure about hitting through, because nobody can express that doesn’t 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, I’m not talking about pure rigid body, because it doesn’t exist.

15. ### sureshsBionic Poster

Joined:
Oct 1, 2005
Messages:
40,498
Didn't you say translation motion is not possible?

16. ### sureshsBionic Poster

Joined:
Oct 1, 2005
Messages:
40,498
Billiard balls are better approximations to rigid bodies than tennis balls.

The intuition means to find the optimum swing path without calculations, which happens with tons of practice and talent. Call it muscle memory if you will.

I really don't folllow the other stuff that you are saying. During the dwell time, there is a forward and an upward force on the ball. And the more the normal force, the more forward force will be imparted.

In physics, mechanical forces are classified as either pull or push forces. In cases of deformation, there is a gray area. The strings that drag the ball with them for topspin may be considered pushing the ball upwards or pulling the ball upwards. But in no case is it pulling in. If the coordinate into the court is considered 0 at the point of contact of the ball and the strings, with the value increasing into the court, then the coordinate of the point on the strings becomes negative during the follow-thru, but the coordinate of the ball never becomes negative. So, at most there is a pulling (or pushing) motion upwards and outwards during the dwell time, but no pulling in motion.

17. ### tolyHall of Fame

Joined:
Sep 2, 2010
Messages:
1,993
Sorry, but I don’t understand the question.

18. ### sureshsBionic Poster

Joined:
Oct 1, 2005
Messages:
40,498
You don't find any contradiction in the above?

In any case, it is not important.

19. ### tolyHall of Fame

Joined:
Sep 2, 2010
Messages:
1,993
If racquet velocity has normal component only (normal to string bed) and point of contact is sweet spot, you hit pure flat FH (forget about strings actions). Because of the absolute symmetry of the ball there always should be solid contact.
If racquet speed has tangential component only, there never will be solid contact.

20. ### bhupaesProfessional

Joined:
Aug 8, 2007
Messages:
957
I think you are right, but it becomes complex when you factor in the wrist layback angle, different grips, etc. Best to experiment and choose what works for you!

21. ### sureshsBionic Poster

Joined:
Oct 1, 2005
Messages:
40,498
Not that simple, because it implies that for any ball, if you want to send it somewhere, you can have the same swing path and the normal component of the force will take care of what you need. That does not happen in practice due to the incoming spin and trajectory of the ball. If you want to send the ball somewhere and it is spinning away, you have to adjust the swing to counteract the topspin, or go with it, depending on what you desire. A ball with no pace and spin needs to be treated differently from one with speed or spin, and the second is not always more difficult, because you can use the incoming pace and spin to advantage. These are the details which the pros handle unconsciously, and are hardly ever discussed in the tennis videos.

22. ### tolyHall of Fame

Joined:
Sep 2, 2010
Messages:
1,993
Yes, the racquet collision with spinning ball is much more complicated.

23. ### julianHall of Fame

Joined:
Dec 20, 2006
Messages:
4,109
Location:
Bedford,Massachusetts,US
A shape of the ball

A ball is NOT symmetric at the contact-see some pictures at the contact time

24. ### 5263G.O.A.T.

Joined:
Mar 31, 2008
Messages:
10,909
"tangential contact and abrupt sideways" are made up by those trying to prove the
impossible; that there is no across aspect to contact that is causing the normal
side aspect we see on normal high level rally Fhs.
Nobody that is sharing the fact, "that there is an across aspect normally to the strokes",
uses either of those terms to describe the action.
Not sure why those 2 straw men continue to show up unless it is the usual shell
game of distraction or an aspect of denial?
Probably right on the OP of why the term MTM is not understood.

Last edited: Oct 16, 2012
25. ### tolyHall of Fame

Joined:
Sep 2, 2010
Messages:
1,993
I’m not going to argue about that, since it is true.

26. ### julianHall of Fame

Joined:
Dec 20, 2006
Messages:
4,109
Location:
Bedford,Massachusetts,US
The absolute symmetry of the ball

So why the "absolute symmetry of the ball" was brought into the discussion?
I do NOT understand the phrase "solid contact" either
Does "solid contact" mean collision of a rigid body with a rigid body?

Last edited: Oct 16, 2012
27. ### tolyHall of Fame

Joined:
Sep 2, 2010
Messages:
1,993
We were talking about solid contact of the racquet with ball.

In post 519 I said, “If racquet velocity has normal component only (normal to string bed) and point of contact is sweet spot, you hit pure flat FH (forget about strings actions). Because of the absolute symmetry of the ball there always should be solid contact.
If racquet speed has tangential component only, there never will be solid contact.”

What is wrong with that?

If carpenter wants to hammer a nail, he also should create only normal component of the hammer velocity to get solid contact, but is not enough, because the nail doesn’t have absolute symmetry. The normal component of velocity must coincide with longitude axis of the nail to provide solid contact.

28. ### julianHall of Fame

Joined:
Dec 20, 2006
Messages:
4,109
Location:
Bedford,Massachusetts,US
Solid contact

I am bringing to your attention that the parallel with a hammer/nail is very "weak"
The nail and hammer are rigid bodies.
A ball and strings are at the different end of the spectrum.
Additionally there are multiple problems with a dictionary/choice of words
for example I do NOT know the meaning of the phrase "solid contact"
Btw:the "if statement" with the the first part of the "if clause" false is always true.
I am talking about the sentence starting with "because"

Last edited: Oct 16, 2012
29. ### tolyHall of Fame

Joined:
Sep 2, 2010
Messages:
1,993
I'm sorry. I'm a foreigner, so my English is not good enough to clearly express some ideas, but I tried my best.

30. ### 5263G.O.A.T.

Joined:
Mar 31, 2008
Messages:
10,909

If JY has any credibility on this above, he is making a play on the ole adage that
Navy Jets don't land on carriers, but instead execute controlled crashes to the
deck. Let's just hope that was his meaning, as I've never costs the tax payers
a cent by crashing a jet or helo, but have saved big \$\$,
by safely returning aircraft with major emergencies. Notice I give him the benefit of the doubt, although
he makes these negative comments on my credibility with the poorly worded attempt above.
I do think the comment is disrespectful to all who have sacrificed greatly to
serve this country, as well as those of us who continue to serve.

31. ### JohnYandellHall of Fame

Joined:
Jun 5, 2004
Messages:
2,014
Well thank god you didn't actually crash one. I can sleep now. No go somewhere and wave the flag for mtm.

Last edited: Oct 26, 2012
32. ### DoctorBackhandRookie

Joined:
Jul 15, 2011
Messages:
311
Location:
New York
Your getting way too personal for an argument over tennis methodologies. Chill out:evil:.

33. ### kiteboardHall of Fame

Joined:
Jun 18, 2009
Messages:
4,557
My uncle had pictures of all the planes he crashed, and walked away from in WW II. Planes in the dirt, in the sand, in the trees, riddled with bullets, and flame, and nothing seemingly wrong with them outwardly other than collapsed wheel housing. My father spent the war in an iron lung, TB, coughing his lungs out for days on end..... My other uncle lost his eye in a tank battle in France with the Nazis who then moved to Argentina. Although tennis is symbolic war, as is every sport, maybe a reason that wars between larger nations are not happening anymore. Endorphins upon the arena are medicine for those who wield the missiles/tanks/ships. I can't say that tennis has stopped me from killing anyone, but it has delayed me from doing so! Wife and customer anger has caused me to "kill" many a practice partner.

For all those posters who wage "war" against each other here, I say time heals all wounds, even those at Normandy... Saw some graffiti on the grave of an American there, and it said, in French, "Take your trash home." Now that's a fellow I'd like to meet and hit him with a tennis racquet or two.. Maybe we should have stayed out of it and let France speak German. Only, it would not have been just France. It would have been Norway, and Sweden, and England, and Luxembourg, and Poland, and etc. I find it strange, that anyone in France, would feel that way about Americans, when my own family bled for them, and didn't have to.

Seems to be an awful lack of gratitude in the world in general. Especially for those who actually do help us improve our games on this site. I'd say, "Thank you.", is more in order for many than the usual disrespectful argument. Yandell is one of those. So, thanks Johh, for helping me.

Last edited: Oct 26, 2012
34. ### JohnYandellHall of Fame

Joined:
Jun 5, 2004
Messages:
2,014
Doctor BH,

Why don't you just worry about your posts and I will worry about mine. "Chill" people are overrated.

35. ### JohnYandellHall of Fame

Joined:
Jun 5, 2004
Messages:
2,014
K-Board,

You're welcome and I have enjoyed our collaboratiion--btw I've got that new aussie poly string Tomic plays with for you to try...

36. ### kiteboardHall of Fame

Joined:
Jun 18, 2009
Messages:
4,557
I'd love to try flex infinity. Want to try the five sided one and the 1.15mm one. Supposed to have great tension loss, and similar poly performance. I see they used the video from one of your pieces of the sideways forehand Peter Mcg. hit in San Diego. http://www.flexinfinity.com/strings/video

Got my winnings today from the singles tournament I won. Scheduled to play another mid month. Hunter G. will be there. Going to practice sequences, lull x 3 cc, and jam x 1 dtl, and finish x 2 cc. Jam x 3 cc/cc, and finish x 1 dtl. Some guys are more susceptible to lull-finish than just lull-jam-finish.

Last edited: Oct 26, 2012
37. ### Ash_SmithHall of Fame

Joined:
Jan 18, 2005
Messages:
4,680
Location:
A green and pleasant land
^^^ "lull"? "jam"?

38. ### arche3Banned

Joined:
Aug 29, 2009
Messages:
5,387
It's a melding of mtm and yandel method. Kind of like being a Jedi.

39. ### treblingsHall of Fame

Joined:
Mar 24, 2008
Messages:
2,815
my favourite practice sequence is the otn&itc-alan variation, imitating the western african grasshopper(male), whilest balancing my inner and outer tp to achieve maximum cs. only downside being, that my socks are stinking after a typical training session oh, well....

40. ### tennis_ballaHall of Fame

Joined:
Mar 16, 2006
Messages:
4,098
Location:
Here and There
41. ### JohnYandellHall of Fame

Joined:
Jun 5, 2004
Messages:
2,014
TB,

Truly a sublime moment in pop tv culture with multiple possible symbolic analogies to repetitive mantras in this thread and others...the only caveat--not sure which way Stewie should be turning the gun...

42. ### 5263G.O.A.T.

Joined:
Mar 31, 2008
Messages:
10,909
Yes, some actually believe the things you post, so I was asked to clear that up by some other posters.
Does show how loose you play with the facts & details.

Joined:
Aug 23, 2006
Messages:
5,471
me thinks Ashe wants to watch...lol

44. ### mntlblokProfessional

Joined:
Jan 15, 2006
Messages:
976
Location:
Savannah
Window Pane

Warning: This is way too long. Don't start it if yer concerned about having yer eyes glaze over. . .

Had never bothered to look into MTM before, but just (finally) made it all the way through this thread. Glad I did. There's lots of interesting stuff, some pretty intelligent folks involved in it, and, believe it or not, I thought more reasonable discussion than what is often seen in online forums.

I *do* think that I've picked up a few "errors" or at least some things that aren't as clear as they might be, and thought that I'd throw in what I think might be some "clarifications", and maybe even a new idea (or, at least, opinion) or two.

The above article by Rod Cross didn't say anything about the "sweet spot" nor its size. Rather, it explained that the spin window (don't think he used that term in the article) is enough larger with a ten inch wide racket than a wooden, nine inch wide racket so that one wouldn't routinely frame the ball with the use of the swing paths, speeds, and face angles that can be used with the modern, lighter materials. He notes in the article
"Give a 9-inch graphite racquet to a player today and the result would be some serious clipping of the frame every few shots. . ."

Toly was exactly right about the perspective from which "sidespin" should be observed and described when speaking of "clockwise-ness". The axis for sidespin is vertical, so you gotta look at the clock face from either above or below. From above, Rafa's forehand sidespin - at least on the "high" ball in the thread, would be counterclockwise.

When Rafa "hooks" one, which I'm pretty certain is only going to happen off a "low" ball, the sidespin would be clockwise.

I don't know what all is actually part of the MTM thing, but the "across" part, as presented in this thread, and what I saw in the video with Mr. Wegner, ain't exactly right. While the the "wiper" follow through does go across, and the "grazing" of the ball by the strings would be (partly) in that direction on a high ball, it *wouldn't* be in that direction on a low ball, but rather, the opposite. That same vertical axis would be spun about in the opposite direction, and the flight of the tennis ball would be seen to curve in the opposite direction.

The cool still photo that Toly posted with Rafa's racket almost vertical was excellent for demonstration of what happens for sidespin on a high ball. I'm betting that a similar photo could be found of Roddick with a near vertical racket, but with the head pointing to the ground, for one of his "hooking" forehands off a low ball. I swear I've seen him "waiting" for a ball to drop low enough so that he could spin it counterclockwise mrgreen off his righty low ball.

I've loved all the photos in this thread where many stages of the racket positions have been shown in one shot. I've been wanting to see these "rainbows" of the "before" contact section of the swing for a long time. I remember one from years ago of the "after", and recall practically begging the guy who posted it (maybe even on tennisplayer.net, with "rainbow" in the description).

My current theory about teaching topspin is that you can put these two rainbows together and come sorta close to laying a pain of glass against the ball striking areas of same, and have both the grip and the stringbed lying against it (the pane). For a righty forehand, I tell folks to imagine a large window pane whose bottom edge runs approximately between their feet (which are in a neutral stance, straddling the baseline) and that same bottom edge lies right on top of the baseline, but with the top of that window pane leaning well forward. These edges are both basically perpendicular to the intended target line.

Next, (and I know this is an over-simplification and isn't exactly accurate) I have them have their racket hand *and* the stringbed make that big "rainbow" move - both before and after contact (and during) - whilst keeping those two parts of the racket lying against that window pane (and pretty much facing the target).

So, the first part of this "rainbow" swing along the "window pane" is actually "left-to-right", with the butt of the racket leading the way, with the stringbed lagging well behind. I don't know that it's universal, but I've watched a *lot* of super slo-mo's of pro forehands (both on YouTube *and* on the various online tennis instruction sites *and* on the cool DVD's {were they "CD's" back then?} that I bought from JY years ago) and I've concluded that the stringbed only catches up with the hand (the long axis of the racket becomes parallel to the ground) at about breast height. Below that height, the player's hand is always above the ball at contact. Above that height, the middle of the stringbed is above the player's hand.

Another relationship that changes with location on the "rainbow" is how far the ball is from the player's body. At the extremes of height, both low and high balls, human anatomy dictates that the ball must be closer to the body. (I haven't thought through the ramifications of whether one uses a bent or straight elbow for these balls).

And, since the window pane leans forward, the higher the contact point, the further out in front contact must in order to maximize the "hit". So, a high ball will be contacted both close to the body line and well out in front. A low ball is contacted close(ish) to the body and much less "out front".

It *may* even be that the rainbow "bows over" a bit more near its top, as I've seen stills of pros with some very closed racket faces way out yonder.

Key to keeping both the hand (grip of the racket) and the stringbed lying "flat" on this pane of glass is that the wrist must be "laid back" (extension?). I was very happy to learn of the "double bend" from JY many years ago. I feel that this position is far too often ignored by the teaching pros that I watch giving lessons - at least, as someone in the thread mentioned - to adults.

One of the reasons that I like to use the "pane of glass" concept rather than a "plane" is that I can describe which part of the racket would cause the pane of glass to "break" if the player changes the plane of his stringbed as it comes counterclockwise around this "rainbow" of a "leaning" clock face from something like six o'clock to twelve o'clock.

If the player "loses his layback" or "flexes" his wrist, then the tip of the racket breaks the glass(and he misses the shot wide).

If he "closes" the racket face beyond what his grip has set up (rolling the face in an attempt to "help" with the topspin), then the top edge of the racket breaks the glass (and he misses the shot into the net).

If he "opens" the face in an attempt to "help" the ball over the net, then bottom edge of the racket breaks the glass (and the ball goes long).

Part of my theory is that the longer the racket face is facing the target (on this "window pane plane"), the greater the margin for error is for "timing" the shot, for both direction and trajectory. One of the online instructors tells me that his coach said pretty much the same thing to him decades ago.

My quest to get at the bottom of what makes a topspin forehand work stems from *many* years of hitting an extremely inconsistent one, myself. Many lessons from many different pros failed to nail down the primary problems. It took a visit to Brian Gordon when he had his operation in Cincinnati a number of years ago to start getting it figured out.

Interestingly, getting hooked up to his wires and his (then) magnets (rather than today's infrared cameras) only exposed *part* of the problem - too steep an upward swing path (with the hand), especially on high balls. *But*, a second serious issue only showed up the next day during the "lesson" part of the program when I was trying to clarify something he was telling me and I demonstrated my backswing "loop" in slow mo and he noticed that I was *opening*, rather than "closing" the face, which, it turns out, then cause me all kinds of problems with trying to get back "on plane" for the forward swing.

BTW, I believe I read in another thread recently that Dr. Gordon can't actually "hit" a tennis ball. Fact is, he can knock the **** out of one on an amazingly flat and controlled trajectory. When I last saw him down in Boca Raton, IIRC, he was thinking about starting to enter some age group tournaments (50's?), in spite of his arthritis issues.

(continued in next post)

45. ### mntlblokProfessional

Joined:
Jan 15, 2006
Messages:
976
Location:
Savannah
Continued

Unfortunately, now that I *think* I'm figuring out how topspin forehands are hit, I can no longer try it, myself - can't lay the arthritic wrist back, anymore. Had a dandy topspin one-handed backhand, but turns out that I used a lot of flexion and extension with that shot, and can't do *that* anymore, either.

Encouragingly, using these same window pane/rainbow swing thoughts, I've been able to teach myself a two-handed backhand. It seems that the theory is robust enough that it works for that shot, too - if I remember to use the left hand for the "spin" part. Unfortunately, I remain stuck with a very ugly-looking, though somewhat effective, batch of slice forehands.

Which reminds me, I've been able to teach a number of folks how to hit topspin forehands off my massively underspun, low-skidding slices. Really good players can already handle them, but even some of the high level, local juniors couldn't get it. The key is using that same "hook" swing that Roddick likes to use - exaggerating the "across" to the right with the racket head way below the hand. BTW, without telling anyone to use a "reverse" finish with this shot, it generally naturally results from that swing.

Which also reminds me, what goes along with the rainbow/window pane stuff is that I like to differentiate between the "hand path" and the path of the racket head or stringbed. I almost think that they have to be thought of as two different beasts.

To me, the "hand path" is what determines how "flat" a swing is and how much "hit" there will be to the shot (ball speed).

The "low-to-highness" of the stringbed is largely, I theorize, the result of how fast the wrist and forearm (and whatever else might be involved) make the racket head move "in the plane of the stringbed". That rate is what Cross and Lindsey tell us is responsible for most of the "spin" (as opposed to "hit") that happens with a tennis ball.

(I know that the "slippery" poly strings are touted highly, but I've yet to see it demonstrated just how *much* additional spin they can add). I *do* know that *I* can, with my \$16 per *reel*, fifteen gauge nylon can cause enough underspin with my slices that the fist bounce after it hits is *still* underspin - and *really* pisses off my opponents when warming up for a doubles match. I always explain that that's all I can do and offer to let them try to play in my wrist brace. :mrgreen:

I'm sure this has been more than enough, but one last thought. For a topspin forehand in a "comfortable" hitting zone, I suspect that one could strike it with pretty much "pure" topspin, with little or no sidespin, having the strings strike pretty much a "straight up" path during the short time that the ball is "dwelling" on the strings. Although, it *would* be fun to talk about how "short" the "across-ness" time is of the string/ball contact that causes the "sidespin". . .:smile:

Kevin
Savannah

46. ### treblingsHall of Fame

Joined:
Mar 24, 2008
Messages:
2,815
i had the same problem myself, still suffering from time to time.
putting everything in one looooooong post

has an upside too, you won´t get critizised a lot, cause not a lot of people will make it thru the post

btw, i like your comparison with breaking the window. nice image to tell to players to make a point

47. ### mntlblokProfessional

Joined:
Jan 15, 2006
Messages:
976
Location:
Savannah
Length

Thanks. It *did* come with a warning. And, I'm used to not being heard. Just happy to share my thoughts if anyone *should* find it of interest. I figured this thread, itself, pretty well weeds out *most* readers.

Kevin

48. ### treblingsHall of Fame

Joined:
Mar 24, 2008
Messages:
2,815
weeds me out lots of times
i often have trouble finding the practical use of the theoretical discussion
if you´re used to not being heard, that probably means you´re a teacher

49. ### 5263G.O.A.T.

Joined:
Mar 31, 2008
Messages:
10,909
Yes, and this may be part of why MTM has it's focus on the path of the hand.
As to the "across-ness", it is my opinion that the across aspect plays a large
role in the trajectory or net clearance.

50. ### mntlblokProfessional

Joined:
Jan 15, 2006
Messages:
976
Location:
Savannah
Trajectory

Interesting. Can't imagine "why". I recall asking a question in a tennis forum early on in my quest about whether trajectory was controlled by racket face angle or by swing path. I was surprised to learn that essentially nobody on the forum seemed to know.

Turns out that it's both, as well as some other factors. I didn't learn about it until reading Chapter 4 in "Technical Tennis" - the best chapter ever written on tennis, IMO. And, if one *really* wants to learn about trajectory, there's nothing better than this: http://twu.tennis-warehouse.com/cgi-bin/trajectory_maker.cgi

Anybody know if "TW University" is done by the same guys who wrote "Technical Tennis"?

Kevin