confused w/ the term "MTM"

[5263]

Originally Posted by toly

Why have you never read messages from other parties carefully? The picture 2 has come from The New York Times video, see please post 135.
I didn’t insert all frames in picture 1 in order to demonstrate the ball’s path clearly. So, you cannot evaluate speed and acceleration of the racquet.

reveal your own, enough already useless words without any proof.

Ok, first, sorry I didn't find that Pic 2 that was on the screen for a couple of secs
during that vid, but to my defense, it was mostly blocked on my screen
by a big pause symbol for some reason.
On the bright side, that symbol was helpful once I located that frame. It was
very useful to show how incredibly inaccurate that stroke path illustration was.
Watching the few secs prior where it had the swing, I could use the pause for
reference to the path and then see how way off the pic two lines were drawn in.
Its not even close. It's like they used something totally different, like say
a traditional perspective on extending the swing path down the target line.
So maybe you also need to look at things more carefully and see there is the
evidence (not Proof of course) you request.

As to accel, why do you bring it up that you don't see it there, then come back
and say it is not set up to use for that purpose? Maybe that is why you don't
see it?

[toly]

Originally Posted by nabrug

Toly,

Why do you want to convince 5263 (and other amatures)? He is a very part time teacher. I am a full time professional who can hit almost every pro stroke. All your observations about the serves and ball trajectories are correct. The MTM observations (up, across and ?) are so naive. Maybe that happens but is so general that you can maybe help an intermediate player. It is not describing the far more complex arm and racket action of the pro's. I am making models of these actions. It is as naive as the Smart Targets System which is already a system and what you can buy next year.

I like your thoughts and studying. Please continue. Answer people like 5263 once and than let them think what they want to think.

I’m retired engineer and have too much free time. But, my brain cannot quit working. So, to keep it busy and happy I decided to analyze tennis strokes from engineer point of view. This is really fun for me.

[Limpinhitter]

Originally Posted by bhupaes

Agreed, absolutely! Equipment has influenced the evolution of the modern game. But my point is, when you are trying to define what the modern game is, where would you fit in equipment? Let's say you watch a Laver/Rosewall game and a Federer/Nadal game and are asked to point out what the differences are. Where would equipment come in, in your description? One can play modern tennis with older equipment, and one can play classical tennis with new equipment. That's why I believe that equipment is not a defining characteristic of modern tennis, although it is a primary enabler. Maybe I am just quibbling and we are all actually in agreement...

Concerning the bolded part, I suppose you could, but, it wouldn't be optimal. In other words, I think Don Budge would play a higher level of tennis with his racquet than Djokovic would, and vice versa.

[toly]

Originally Posted by 5263

Ok, first, sorry I didn't find that Pic 2 that was on the screen for a couple of secs
during that vid, but to my defense, it was mostly blocked on my screen
by a big pause symbol for some reason.
On the bright side, that symbol was helpful once I located that frame. It was
very useful to show how incredibly inaccurate that stroke path illustration was.
Watching the few secs prior where it had the swing, I could use the pause for
reference to the path and then see how way off the pic two lines were drawn in.
Its not even close. It's like they used something totally different, like say
a traditional perspective on extending the swing path down the target line.
So maybe you also need to look at things more carefully and see there is the
evidence (not Proof of course) you request.

As to accel, why do you bring it up that you don't see it there, then come back
and say it is not set up to use for that purpose? Maybe that is why you don't
see it?

About approximation:
Here is picture that combines the racquet path and its approximation from New York Times. It seems they did very good job.



If you know any better approximation algorithm, just let me know. However, I must warn you that no one has yet invented a perfect approximation.
About acceleration:
Did you read post 137?

[Cheetah]

Wouldn't be difficult to determine rhs from a graphic like that because that kind of pic only shows the horizontal movement? What about the low to high movement and the wrist flex and pronation which all contribute to the speed of the face. You can't really see the wrist and forearm movement contributions in that pic only horizontal movement of the entire racquet. no?

So even if the arm itself isn't accelerating at contact the racquet head should be because of the above movements. You can't see wrist and forearm movements in that pic but we all know it's there and with nadal he uses a lot.

[5263]

Originally Posted by toly

About approximation:
Here is picture that combines the racquet path and its approximation from New York Times. It seems they did very good job.

About acceleration:
Did you read post 137?

acceleration... you brought it up in 135 I think with this..."There also is no
compact swing and sudden, 3” before impact, racquet acceleration."

Then you come back in #137 and say, "So, you cannot evaluate speed and
acceleration of the racquet."

So first you claim that sudden accel is not there
(never mind MTM does not claim sudden accel),
then come back and say it cannot be evaluated.
I'm just asking, which way you want it?? Are you going to claim it's not there
or claim it cannot be evaluated from the info??

And NO, that is a very poor job with the illustration and shows several inches,
if done to scale, of straight forward swing where there is none and has the
last part of the straight section up at the frame instead of the middle where
it started and was tracking! Those are the critical inches
where the face is coming across. The small straight section would be the
lead in and rt before contact the face is coming across at greater than the
angle this illustration has at the end of it's straight segment. Don't want to be
mean, but surely you were not that sloppy with your work as an engineer, right?

[boramiNYC]

in my view toly's latest graphic from NYT is pretty accurate depiction of how I imagine Nadal's swing path would be. it's from the top view so the vertical path can't be seen but it's surprising how little pulling across there is on that graphic. don't want to knock MTM, just saying. 5263 your latest comment sounds pretty harsh kinda unbecoming.

[5263]

Originally Posted by boramiNYC

don't want to knock MTM, just saying. 5263 your latest comment sounds pretty harsh kinda unbecoming.

Hey, I will apologize. But, must say I'm quite astounded. Just shows how 2 folks
can look at the same thing, but see it different. I don't know what you expected
to see but the swing is just what I knew it would be and is critically different
from the pic#2. I'm not surprised some won't get the importance of it, but
for you and an engineer...I'm sort of floored.
But I do apologize if I've been unbecoming and don't really intend to be harsh so
much as to drive an important point.
And thanks for letting me hear that in a direct and positive way. I'll work on it.

[5263]

wish I had somewhere to send my version of that pic with the proper line
drawn for the path, so to show what a huge difference it makes. tinypic
was not working for me.

Don't you see how the fat yellow line is inside the contact point at contact,
(instead of over the contact area)
then well outside the contact point in the next ref pt?
(again, instead of over the contact area)
Proper line should be more than 30 degr off of the target line.
What did you expect?

[connico]

Click to view full size!

That ok?

[boramiNYC]

5263, i see your point. the overlay is not perfect and the line wans't drawn with good precision. but mostly that's after contact and i think the one who produced the graphic wanted to show the rac path before the contact and how closely it follows the line of target, which it does. no worries tho for mtm that motion is before the contact and not through the contact. and nadal is not the best example of true pull across swinger. so maybe it's no big deal?

[5263]

Originally Posted by boramiNYC

5263, i see your point. the overlay is not perfect and the line wans't drawn with good precision. but mostly that's after contact and i think the one who produced the graphic wanted to show the rac path before the contact and how closely it follows the line of target, which it does. no worries tho for mtm that motion is before the contact and not through the contact. and nadal is not the best example of true pull across swinger. so maybe it's no big deal?

Yes, mostly, but it's the part after the contact that is contested and is what
differs from classic.
good points though

[5263]

Originally Posted by connico

That ok?

way better for sure and now does not give that
hit thru 3-5 balls look to it,
close to what I had.
thanks

[toly]

5263:acceleration... you brought it up in 135 I think with this..."There also is no
compact swing and sudden, 3” before impact, racquet acceleration."

The acceleration 3” before impact is Wegner recommendation. I think it came from martial art and jumpulse.com.

Then you come back in #137 and say, "So, you cannot evaluate speed and
acceleration of the racquet."

You cannot evaluate speed/acceleration from my picture, because I removed some frames to show ball’s path. Again you don’t read my posts carefully.

So first you claim that sudden accel is not there
(never mind MTM does not claim sudden accel),

It did many times.

then come back and say it cannot be evaluated.
I'm just asking, which way you want it?? Are you going to claim it's not there
or claim it cannot be evaluated from the info??

You can evaluate it from original video.

And NO, that is a very poor job with the illustration and shows several inches,
if done to scale, of straight forward swing where there is none and has the
last part of the straight section up at the frame instead of the middle where
it started and was tracking! Those are the critical inches
where the face is coming across.

Everybody can say about any approximation that this one is very poor. This one is excellent, explanation below.

The minute straight section would be the
lead in and rt before contact the face is coming across at greater than the
angle this illustration has at the end of it's straight segment. Don't want to be
mean, but surely you were not that sloppy with your work as an engineer, right?

Nadal rotates his straight arm about shoulder. From shoulder joint point of view, the wrist moves along a perfect circle, because Nadal arm is constantly straight. So, this rotation is absolutely symmetrical relative to the shoulder joint.
If angle between arm and long axis of racquet (ϕ) is zero, there would be no “across aspect” at all. This is just simple geometry. If ϕ=90°, there would be maximum “across aspect”.
Nadal begins rotating his arm with ϕ=90°, if he hits ball in the beginning of the forward swing he could produce maximum “across aspect”.
But, Nadal also rotates the hand around the wrist. Thus, he decreases ϕ angle and inevitably reduces across component of the racquet speed.
Btw, these two independent rotations can move tip of the racquet exactly along the straight line. Even people from New York Time understand that, and they drew partially straight racquet path. They are really smart guys.
Please forget about MTM and try to analyze the matter with open eyes.

[sureshs]

Originally Posted by toly

Here is very good analysis of the typical Nadal FH racquet path http://www.nytimes.com/interactive/2...-Forehand.html.

The picture 1, clearly demonstrates that around impact, frames from #5 to #7, there is no “special” horizontal across motion at all. It occurs after impact, frame #9.



The picture 2 shows that during contact racquet’s path is almost straight forward. IMO, it must be this way if we want to hit powerful FH.

There also is no compact swing and sudden, 3” before impact, racquet acceleration.

So far I see zero correlation between Wegner recommendations and real professional game. That’s why virtually nobody can comprehend MTM. We cannot see what is not there.

Excellent analysis. It is clear that Rafa does not hit 3 balls in a row.

He hits 5.

The overlap in Fig 2 between the racket path and the ball path is telling. The racket clearly moves in the direction of the intended target for the large part, before turning over, as it must.

There is also no abrupt acceleration before impact. The speed keeps increasing, but as per your next post, the acceleration is actually decreasing before impact. The human body cannot sustain continued acceleration of a limb, and that too without sacrificing control.

[sureshs]

See this article:

http://www.pbitennis.com/_blog/Tenni...ollow-through/

[Cheetah]

Originally Posted by sureshs

See this article:

http://www.pbitennis.com/_blog/Tenni...ollow-through/

Good article w/ Good pics.

[5263]

Originally Posted by Cheetah

Good article w/ Good pics.

Nice article with good pics that show clearly on Fh and Bh how the racket
has moved well off the target line shortly after contact.
Clearly he means the very general direction of the target, instead of directly
out towards the target.
It's even more clear that some will see what they intend to see, even after
connico did a pretty good job of fixing that poor NYT illustration pic.

[5263]

Originally Posted by toly

try to analyze the matter with open eyes.[/color]

I give you back your own advice above...This must be a language barrier situation.
Clearly there is no straight part to the vid of the swing from contact to finish.
Connico improved the pic 2....did you see that correction?

[Cheetah]

I don't think it's really possible to settle anything w/ that graphic. You would 1 more angle of the same shot at least. In real life his shoulder joint isn't just sitting there stationary in one location. It's moving with his shoulders. And it's moving with his body. And he's also pushing up with his legs. And his wrist is doing things. And his forearm is pronating. And he's also probably moving a little bit forward maybe. And maybe he's pushing up on a slight angle etc etc. There's a lot going on you can't see from only a top down view.