The fast low bouncing version of the Bigservesofthands first serve

Given that there seems to be sufficient interest in the fast low bouncing low net clearance version of my first serve, I am going ahead and starting a thread to discuss it.

I use it occasionally say 1 in 15 times at the beginning of a playing session and use it much more frequently (say 1 in 4 times) towards the end of a 2-3 hour playing session when the explosive leg drive needed for the for traditional serves is harder to come by. I am able to execute it with about 50% success rate in match play. I think the actual rate is likely slightly higher because opponents usually give themselves the benefit of the doubt on line calls and serve targets an area close to the service line.

I can serve in the low teens with this motion. Can crank it up to 120s at the cost of accuracy (mostly hitting long, directional accuracy is still present).

I think it would be a good option as a change up for a taller player who has played a pitching sport before and is in need of a fast easy action resting serve that does not require the more elaborate energy sapping service motion of a traditional serve. Or as a cranked up change up low bouncing slider if used as an attacking option.

Here are three videos that show the serve from all three angles (from behind, from the right side and the left side).







Now I will explain how the surprisingly large amount of racquet head speed is generated using this serve.

Below are the three important frames that describe the loading phase.

2zt9ax5.png


The first is the power position before the start of the trunk rotation, second is the maximal elbow raise as the cartwheel occurs, the third is the maximum shoulder raise position right before the start of butt cap drive towards the ball and extension of the the forearm.

I used to be genuine fast bowler in cricket in my youth capable generating over 85 mph bowling speeds. In cricket pace bowling much of the speed is developed by planting a straight extended front foot at the bowling crease and transferring the resulting ground force impulse to the ball. A larger horizontal (braking) impulse is associated with a faster ball speed and a larger plant angle of the front leg (measured from the vertical) at front foot contact is associated with a larger horizontal impulse. One of the key determinants of ball speed in cricket (and baseball) is the horizontal impulse generated at the ground over the period from front foot contact until ball release. A fast bowler with a full run up can generate peaks of 15 times their body weight of ground impulse at ball release. Baseball players generate over 2 times body weight of ground impulse at release.

The ground force impulse in cricket bowling is powerful enough to explode shoes like in this incident

https://vine.co/v/O9m2qqKA1aY

I had a few pairs explode on me like that in my youth.

As you can see in frame one above I have a large plant angle and from the first video you can see my front foot, shuffling, planting and forcefully pushing down and generating a large ground force impulse in the time period between maximal elbow raise in frame 2 and maximum ISR stretch in frame 3.

The only pro player that I have seen use a similar front foot shuffle and push off but with different timing is Mikhail Youzhny


In a very short period of time between these two positions (elbow raise to shoulder raise) I have converted the rotation of the truck and the ground force impulse into a pretty significant ISR stretch by the time I reach the position in frame 3 when the forearm drive to the ball starts. The timing of this lower body drive is very different than a regular serve where it happens much earlier (right after power position). So my SSC is much more shortened than the traditional serve SSC and hence I believe more powerful. The only other server who uses this delayed leg push timing that I found was Rosco Tanner.

j9vsqg.png


As you can see from his sequence below he pushes down on his legs and barely gets off the ground in the frames between traditional racquet drop and maximal shoulder stretch. Roscoe is known to have generated 2 times body weight or more of ground force reaction.


Another similarity that I share with Roscoe is the quick mostly horizontal swing loop. The closest analogue among the current pros is Bernie Tomic (don't know why folks with unsavory personal lives seem to have such novel and interesting service motions).

When I really go for it while executing this serve, I generate significant ground force impulse. In the first year of taking tennis I bought toe box reinforced adidas barricade shoes. The ground force impulse being generated by my hard serves while wearing these reinforced shoes crushed my left big toe and caused the toe nail to turn blue and fall off. I had to return those and go to softer shoes. I also had to resort to cutting a hole in the toe and keep that pair handy like I used to do in my cricketing days to avoid the same situation.

https://www.quora.com/Why-do-fast-bowlers-tear-the-front-part-of-their-shoes

I went to graduate school at UW-Madison. While there I played intramural baseball and ice-hockey. Picked up pitching pretty easily given my pace bowling background. Took a winter to learn to skate well and the next winter I learned how to hit the slap shot. Loved that stroke.

I came to this forum to get advise on this serve about a year ago and got some encouragement and a fair share of ridicule.

It wasn’t until the middle of last year that it all clicked for me when I saw Roscoe’s serve. I studied my service motion in greater detail and researched the biomechanics of cricket, baseball and ice hockey. Only then was I able to understand what was going on and why my body was producing the serve the way it did.

My serve has a horizontal tennis swing loop with elements of the cricket bowling action (plant angle, front foot plant, ground force impulse ..), mixed with a baseball pitching action (use of bent elbow not allowed in cricket, shoulder loading and ESR-ISR SSC) and with a ice hockey slap shot tacked in the end (the dominant hand portion). They were well tied together, nicely timed and the resultant action generates easy, controlled and effortless pace that I can keep up for hours.

It was discouraging earlier when people called it wild and uncontrolled on this forum. It was no worse in its misses (people with far weaker serves hit longer and wider than me and there are plenty of kick serve wielders that I encounter who serve into the next court at least once or twice a session) than even the highest level peers I played with. The percentages were not bad either (I have yet to encounter at the rec level a player with a first serve that is above the 50% level who has a non-attackable first serve) and it suits the first strike tennis that I play. Anyways people who play me regularly are used to it now and have changed their perceptions. Most seem to enjoy the challenge of returning it and the easy power they can harness even with just a continental grip bunt back.

Anyways I am fond of this stroke. I think it is nice looking and it does what it supposed to, get the ball to whiz past returners or throw up easy sitters to put away.
 
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Digital Atheist

Hall of Fame
This is actually a really interesting way to look at the delayed leg drive (as you call it) because I've noticed that in addition to Tanner, there are a couple of other big servers who have used the same kind of approach - namely Benjamin Becker and Goran Ivanisevic (there may well be others but it is an uncommon technique and I can't think of any). I always wondered how they managed to generate such blinding speeds and you may well be onto something.



In the 4th frame above Becker has just initiated leg drive and the racquet is well past the recommended power position. I believe it's also called "leaking in" by Macci and others, and is generally NOT recommended as a way of generating racquet head speed. In fact, it is discouraged and is considered to be the cause of power loss and NOT gain.

www.youtube.com/watch?v=0vc3_pUFSgI

That video has been linked repeatedly on this forum, but it really is interesting to watch from about the 11 minute mark (17 minutes is where the leakage is mentioned). My 2 cents; I believe the delayed leg drive definitely does work for the few mentioned above including OP, but they are unique and seem to be the exception rather than the rule. Another observation; those who make it work have low ball tosses and very fast motions (this could be a coincidence). Given practically every other elite server seems to use leg drive to initiate racquet head speed from the standard power position, surely that approach would be considered the most efficient method, no? And there certainly seems to be more leakage on the WTA where serves are, in general, more problematic. It's not that the delayed leg drive/racquet leakage is wrong per sae, but rather that it appears biomechanically harder to synchronise, and most who use it seem to have weaker serves. In short, I really don't see it as an easy option, but maybe there's a way to teach it and make it work?

Just an opinion however and food for thought.

I have yet to encounter at the rec level a player with a first serve that is above the 50% level who has a non-attackable first serve

Wow, then consider yourself lucky because they exist and I'm guessing it will happen!
 
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Dolgopolov85

G.O.A.T.
My finish is similar to yours, as in the right leg tailgating and finishing front of the left foot (as in your third video). I too played cricket, albeit only in school, and loved to run in hard and bowl. Let's not talk about the pace, though, ha ha.
 
This is actually a really interesting way to look at the delayed leg drive (as you call it) because I've noticed that in addition to Tanner, there are a couple of other big servers who have used the same kind of approach - namely Benjamin Becker and Goran Ivanisevic (there may well be others but it is an uncommon technique and I can't think of any). I always wondered how they managed to generate such blinding speeds and you may well be onto something.



In the 4th frame above Becker has just initiated leg drive and the racquet is well past the recommended power position. I believe it's also called "leaking in" by Macci and others, and is generally NOT recommended as a way of generating racquet head speed. In fact, it is discouraged and is considered to be the cause of power loss and NOT gain.

www.youtube.com/watch?v=0vc3_pUFSgI

That video has been linked repeatedly on this forum, but it really is interesting to watch from about the 11 minute mark (17 minutes is where the leakage is mentioned). My 2 cents; I believe the delayed leg drive definitely does work for the few mentioned above including OP, but they are unique and seem to be the exception rather than the rule. Another observation; those who make it work have low ball tosses and very fast motions (this could be a coincidence). Given practically every other elite server seems to use leg drive to initiate racquet head speed from the standard power position, surely that approach would be considered the most efficient method, no? And there certainly seems to be more leakage on the WTA where serves are, in general, more problematic. It's not that the delayed leg drive/racquet leakage is wrong per sae, but rather that it appears biomechanically harder to synchronise, and most who use it seem to have weaker serves. In short, I really don't see it as an easy option, but maybe there's a way to teach it and make it work?

Just an opinion however and food for thought.



Wow, then consider yourself lucky because they exist and I'm guessing it will happen!

Thanks for the Benjamin Becker pointer. I have not studied him before. I did study Goran. Yes Goran does delay his drive but the delay is more subtle and the footage lower frame rate, so I did not mention him.

I forgot to mention the one server that I have studied extensively and modeled a lot of my timing after for this leg whip type of serve and that server is Taylor Dent. Here is is sequence from power position, elbow raise, shoulder raise and then into contact.

23h5e8x.png


As you can see he splits his drive into two one for the back leg and one for the front. The back leg drive get the swing loop going, I do the same but with more of a plant angle and less knee bend than Taylor. His front leg drive is timed for the shoulder raise just like mine. He keeps the ground force impulse going nearly till contact and I attempt to do that as well. In my experience back loading as much of the drive as close to shoulder raise as possible maximizes serve speed and Roscoe does that. Taylor spreads it out a little more.
 
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onehandbh

G.O.A.T.
bigservesofthands, it looks like your service motion works for flat and serves with some slice, but it looks like it might be difficult to hit a kick or twist serve using that motion b/c without much of leg drive/torse turn/shoulder tilt, it will be harder to get your body into the "chest facing the sky" position that makes it easier to hit a kick serve.

Can you post a video of your kick serve? I'm curious how you hit it. Your motion is quite unique in the way it generates so much power.
 
bigservesofthands, it looks like your service motion works for flat and serves with some slice, but it looks like it might be difficult to hit a kick or twist serve using that motion b/c without much of leg drive/torse turn/shoulder tilt, it will be harder to get your body into the "chest facing the sky" position that makes it easier to hit a kick serve.

Can you post a video of your kick serve? I'm curious how you hit it. Your motion is quite unique in the way it generates so much power.

I hit kick serves with a completely different motion and swing loop and path. More traditional. I do exaggerate things a bit in that I swing much more parallel to the baseline than traditional servers and yes there is no slap at all there. Very edge on. More chest facing the ball, knee bend, ankle lift and drive up to the ball. Toss is over my head and closer to the baseline rather than the aggressive 1-2 feet inside that I use with this low bouncing first serve. But I retain some elements of the current serve like leg drive timing. All serves now done with a quick action low toss for disguise. People can't easily tell what is coming till closer to ball contact when the lower body differences and contact height become apparent.

I will try to get some footage.
 

Digital Atheist

Hall of Fame
As you can see he splits his drive into two one for the back leg and one for the front. The back leg drive get the swing loop going, I do the same but with more of a plant angle and less knee bend than Taylor. His front leg drive is timed for the shoulder raise just like mine.

Again, very interesting interpretation. I can't really tell if there is any separation of the legs from those images as I simply cannot detect muscle activation. I have to say I am sceptical that any high level server uses two distinct and separate leg drives on the serve, but that doesn't mean it isn't happening. Could it not be that the front leg is just "along for the ride" and that the small amount of air he gets from it is merely a result of his back leg drive and upward swing? Isn't it even possible that the opposite is true - and the back leg is lifted and comes up somewhat passively as a result of the front foot ground forces he applies and his upward swing? Or he uses both legs at the same time but one is more dominant. Is there really a way to tell? I don't know (Chas?).
 
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LeeD

Bionic Poster
I can hit a decently fast low serve, about mid thigh at the backwall, 21' behind the baseline. Barely 100.
What I need to learn is a high bouncing FAST serve, something around upper chest to shoulder high, and something I USED to be able to do on abrasive courts, HarTru or newly painted cement, in my old days 35 year's ago.
Adding more slice component lowers the bounce, but I'd like a high bouncing fast serve in my choices.
Maybe I gotta go back to holding the racket slightly different, more backhand style, with conti grip, swing upwards with closed racket face (facing slightly down)
 
Again, very interesting interpretation. I can't really tell if there is any separation of the legs from those images as I simply cannot detect muscle activation. I have to say I am sceptical that any high level server uses two distinct and separate leg drives on the serve, but that doesn't mean it isn't happening. Could it not be that the front leg is just "along for the ride" and that the small amount of air he gets from it is merely a result of his back leg drive and upward swing? Isn't it even possible that the opposite is true - and the back leg is lifted and comes up somewhat passively as a result of the front foot ground forces he applies and his upward swing? Or he uses both legs at the same time but one is more dominant. Is there really a way to tell? I don't know (Chas?).

Here you go.

2Kcd0KR.gif


Hopefully you can see the back leg fire and then the front leg.
 

Digital Atheist

Hall of Fame
^^^ Yep that's much clearer. Definitely back leg driving the upward thrust initially (I've read the back leg is often under utilised in the platform stance). I wonder how many other platform servers use this method.
 
The interesting thing to note about Dent and Tanner is they keep the ground force impulse going till near contact. The intent is not to get into the air but to push down into the ground and also exert a braking influence on the trunk rotation so that a lot of that inertia can be transferred to the shoulder as a ESR stretch. This results in much larger loading of the shoulder for a much smaller amount of trunk body movement than a regular serve. In a traditional serve once you are in the air the only thing that you can use is movement of the non-hitting arm and shoulder to provide the braking resistance which is much less in magnitude than pushing down on the ground. You obviously lose some contact height in this process which is the tradeoff that you are making for the increased serve speed.
 
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Here is how I plant my front foot and then fire my back foot to start the swing loop and then fire my front foot to load the shoulder at the last possible moment which is the shoulder raise.

2WlNPuH.gif
 

Chas Tennis

G.O.A.T.
.............. Or he uses both legs at the same time but one is more dominant. Is there really a way to tell? I don't know (Chas?).

I've been wondering about the footwork and the interesting variety that I've seen, and I have the same questions that you are asking. No progress to speak of.

First is to study the videos. Tanner was explosive with a very low toss as some other big servers. But I could not see why he had a big serve by looking at his feet, the back foot seem to come forward without showing anything that looked like strong forces. ??. Unfortunately, I've found no high speed videos from Tanner's prime playing years. Interestingly, looking at servers in general, I often wonder if one of the feet did anything. ?

Thread on Tanner's serve. Some footwork pictures, more leg pictures, are in the thread.
http://tt.tennis-warehouse.com/index.php?threads/roscoe-tanners-big-serve.547499/

Closeup of Tanner serve at about 1:11.

One general point is that a portion of forward momentum can be converted to upward momentum by using the front leg. Another point is that each leg applies its force at the hip joint. The two forces, one at each hip, affect the pelvis producing varying combinations of rotation, forward motion and upward motion. How the pelvis motion affects the body above the pelvis depends on the positions of body parts the states of muscles (relaxed, activated muscle forces, stretched muscles, etc). The Trophy Position is an example of body part positions and muscular states when the legs apply forces.

There are some publications on the pin point and platform stances. One said the resulting pace was similar between the two techniques.
 
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Earlier you described the exploding shoe from stopping hard.

Does that relate to this video?

That refers to the foot plant that was not shown in the above animated gif. The one below shows it

rqEeshv.gif


As you can see the back leg fires first, then front leg straightens and plants and pushes down for a while trying to put a brake on the torso rotation and then fires to load the shoulder from between shoulder raise to elbow raise.

Keep in mind that these are easy low effort versions of the serve. In the high effort ones used in practice when going for aces, the back leg is more towards the back left corner and the rotation is much more vigorous and the foot plant is far more violent. Nothing like a 85 mph+ cricket delivery but pretty forceful nevertheless.
 

Chas Tennis

G.O.A.T.
Very interesting and the video is ideal to examine this issue. Still footwork is hard to analyze.

Do you think the front or back leg pushes up the most?
 
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Very interesting and the video is ideal to examine this issue. Still hard to analyze.

Do you think the front or back leg pushes up the most?

The back leg fires when the body has nearly come to rest in the power position. I feel like that this initial back foot impulse might be stronger than the front foot push off, since it is getting a pretty large mass to start moving from rest. But is lasts for far less time as hips fire very soon after and then it goes airborne along for the ride. The pressures exerted on the front foot however feel much stronger and last longer and happen thrice in quick succession - front foot plant and body brake, front foot push off and front foot land.
 
I can hit a decently fast low serve, about mid thigh at the backwall, 21' behind the baseline. Barely 100.
What I need to learn is a high bouncing FAST serve, something around upper chest to shoulder high, and something I USED to be able to do on abrasive courts, HarTru or newly painted cement, in my old days 35 year's ago.
Adding more slice component lowers the bounce, but I'd like a high bouncing fast serve in my choices.
Maybe I gotta go back to holding the racket slightly different, more backhand style, with conti grip, swing upwards with closed racket face (facing slightly down)

I am able to hit both high bouncing fast in addition to the low bouncing fast being discussed. The high bouncing one has a large kick component to it. Very different swing paths, different timing, different contact points on the ball.The racquet head speed is so high for the high bouncing fast serves that I cannot really tell with accuracy what kind of brushing motion happens. My feel and muscle memory cues for the high bouncing serve are approach from the right (the righter and steeper the approach to the ball the higher the margin), hit as outside of the ball as I can and as close to the top left of the ball as I can and hit it before I have fully squared to the net). I can control the direction by the angle on the face at contact and by pointing my front foot in the direction of the serve during push off. This is a higher percentage serve (near 60%) where I am going for pace using a smaller approach angle and hit through the ball. Second serve kicks are a variation of this serve - far greater approach angle (nearly parallel to the baseline), far steeper approach by attempting to really get under the ball, and attempting to go over the top of the ball if I can. I have had some dive so steeply that a few hit less than a feet from the net causing head shakes from opponents. It took a lot of work and practice to get it to this level.
 

Digital Atheist

Hall of Fame
Very interesting and the video is ideal to examine this issue. Still hard to analyze.

Do you think the front or back leg pushes up the most?

Good question. And as far as platform servers go, to me it looks like Fed is pretty much on par with Dent as far as the timing goes:

Federer_Leg-Drive.gif


Back leg appears to drive a tiny fraction before the front, but I opine that this is just a natural result of the body when driving off both together in an up and forward movement. I don't think the leg drives on a high level platform serve are consciously separated, and such a thing doesn't seem to be taught by the likes of Salzenstein who advocates for platform (I could be wrong). BSSH on the other hand has a major separation between leg drives and it is easily discernable, but damn that must be hard to do without breaking the chain!

There's another way to look at this. With all the variation - as you have pointed out Chas - perhaps the way in which the legs drive isn't as important as what preceded and what follows. As long as the leg drive initiates the racquet drop/correct upward swing from some form of trophy position, it may not be critical to producing good pace? For example, there are servers like Almagro who seem to use very little back leg drive but can still deliver bombs, which would indicate to me that, although I do believe the back leg thing is something to focus on, it's not as important as other aspects that are real power killers.
 

sureshs

Bionic Poster
You almost foot fault. In some of the videos, your left foot is on the line and when you hit the ball, it goes up, and probably avoids a FF! You are very close to FFing.
 
You almost foot fault. In some of the videos, your left foot is on the line and when you hit the ball, it goes up, and probably avoids a FF! You are very close to FFing.

These are practice serves. I have good check points to make sure I don't. My foot plant is measured to fall before the baseline. With good leg drive I contact the ball with feet off the ground.

Plenty of ATP players (Granollers, Gilles Simon, Wawrinka ....) hit with the same foot fault margins I have (in the practice serves) in actual competition and the line judges seem to have good enough eyes not to call them.
 

LeeD

Bionic Poster
I am able to hit both high bouncing fast in addition to the low bouncing fast being discussed. The high bouncing one has a large kick component to it. Very different swing paths, different timing, different contact points on the ball.The racquet head speed is so high for the high bouncing fast serves that I cannot really tell with accuracy what kind of brushing motion happens. My feel and muscle memory cues for the high bouncing serve are approach from the right (the righter and steeper the approach to the ball the higher the margin), hit as outside of the ball as I can and as close to the top left of the ball as I can and hit it before I have fully squared to the net). I can control the direction by the angle on the face at contact and by pointing my front foot in the direction of the serve during push off. This is a higher percentage serve (near 60%) where I am going for pace using a smaller approach angle and hit through the ball. Second serve kicks are a variation of this serve - far greater approach angle (nearly parallel to the baseline), far steeper approach by attempting to really get under the ball, and attempting to go over the top of the ball if I can. I have had some dive so steeply that a few hit less than a feet from the net causing head shakes from opponents. It took a lot of work and practice to get it to this level.

Thanks, I was referring to hitting flat first serves, not spin, not kick first serves.
 

dunlop_fort_knox

Professional
i notice when I stay grounded I serve better. look at pancho gonzales. did not jump at all and grounded himself on the serve. I don't believe jumping is necessary to have a big serve.
 

LeeD

Bionic Poster
To have a big serve, jumping is not needed.
To have a big serve that goes in at a decent percentage, us short guys have to reach up as high as possible, and jump just a bit to get a better angle at the opponent's service court.
Standing flat footed, I can reach up to around 7'4". BSHands can probably reach 8'6". His "vision" of the service court is a lot bigger than mine, so a little jump helps a little bit.
 
So far I have only partially answered how I generate the racquet head speed in that I have only dealt with how I load my shoulder differently than how traditional servers do.

I will now describe the novelties in the release phase which make use of the increased shoulder loading effectively to generate more racquet head speed than in a traditional serve’s release.

In a traditional serve the ESR loading is mostly completed as soon as the leg drive and racquet drop occur. There is a small additional stretch that a small minority of servers add during shoulder raise phase. Forearm extension occurs after shoulder raise with the racquet mostly edge while it drives to the ball and then finally around half way between big L and contact whatever shoulder stretch that remains in the ISR muscles (which has not leaked out between racquet drop and elbow extension) is quickly released, the ESR muscles fire at the same time and the entire shoulder rotates the straight arm with the racquet held by the wrist at a 45 degrees. The amount of rotation is about 90 degrees.

Here is what the three versions of traditional serve’s release phase look like.

niQ4iAy.gif


In the case of my serve, the loading phase is much delayed and does not complete until after forearm raise and wrist lay back.

I load my shoulder initially with the front foot plant that is timed with my version of the racquet drop. The front foot plant puts a brake on the torso rotation initiated by the back foot and hips. This braking impulse is converted into a shoulder stretch in the first phase of shoulder loading.

In the second phase the front foot leg drive timed with the shoulder raise is fired which loads the shoulder even more.

The loading continues in the third phase as I raise my forearm and point its flat face to the back fence. This phase loads the forearm as well.

The loading continues some more in the third phase as I lay my wrist to the side and point the racquet face up with its tip pointing to the back fence right corner. This phase loads the forearm even more and adds a loaded wrist to the mix as well.

When I complete my loading phase the racquet is now in a position to let the shoulder rotate internally more than 180 degrees (my ball toss is well into the court and the wrist is laid back past horizontal) into contact using the same forearm to racquet angle of 45 degrees as the traditional serve.

Here is what the second, third and fourth loading phases and the release to contact of my serve looks like.

ZyT3t0X.gif


The release phase of my serve starts much later than traditional serves. During release, I am able to bring to bear more than twice the ISR acceleration of a traditional serve. I retain the forearm raise component of the traditional serve and am able to incorporate some of the ulnar deviation component of it as well into the internal shoulder rotation and wrist roll. Wrist flexion is not the major component of the racquet’s drive to contact. It is ISR, forearm pronation and wrist flexion in that order. So for the loss of a part of ulnar deviation, I bring to bear twice the ISR and forearm pronation and a much larger wrist flexion during release. So it is no wonder that the RHS I generate is higher with this motion than with the traditional motion. I am able to do both and this anomaly led me to dig deeper and figure out what exactly was going on.

Some doubts were raised in other threads on the RHS, I am able to generate using a face on approach by bringing in concepts of classical mechanics like the mass moment of inertia of a tennis racquet.

Below is a figure that describes the three MMOIs of a tennis racquet (lateral - the one involved in ulnar deviation, polar - the one which supposedly closes the face in a traditional serve and transverse which is the one involved in the approach to contact of a pure waiter’s tray serve). The argument seems to be that since it is much more easier to move the racquet laterally and to spin it along the polar axis than it is to rotate it transversely, much more RHS is generated by a traditional serve than a serve like mine which has a large transverse rotation component.

KtaOaGL.png


This argument has a number of fallacies

  1. In a traditional serve most of the RHS at release past big L is generated through ISR with the racquet at a 45 degree angle to the forearm. So it has the same transverse rotation component as my serve (but half as much) and this transverse component is the largest determiner of RHS in this serve.
  2. It ignores a two big determiners of final RHS which are the angular deviations involved (twice as much in my case) and the rotational power stored and released (which is much larger in my case).

So yes, I experience higher RHS and can explain why it happens and am able to use the insights gained to keep improving my serve.

I also am in the process of improving the traditional serve by incorporating components of my fast low bouncing serve to it. This allows for retaining the advantages of the traditional serve while injecting the benefits of my natural serve into it.
 
There was a question by Retrospin about how parametric acceleration comes into play.

If you look at the racquet MMOI picture above, as the racquet rotates with a mixture of transverse and polar rotation towards the racquet with the racquet aligned at 45 degrees to the extended forearm after ulnar deviation is completed, the racquet tip traces an arc toward the ball.

In the case of my serve with the wrist laid back, the arc is much larger.

I can bring parametric acceleration into play by pulling the butt cap towards the centre of the arc. This gives the following benefits

1. It accelerates the racquet head even further
2. It gives a larger "high point", where the racquet head is accelerating but not closing so fast. This gives me better control in timing the stroke, aiming for sweetspot etc.

In the traditional serve, I cannot bring parametric acceleration into play because the wrist is not laid back and obstructs any pulling and the arc is smaller giving much less time to bring it into play. I am working on some adjustments to make it possible in a traditional serve, but they are works in progress.
 
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julian

Hall of Fame
There was a question by Retrospin about how parametric acceleration comes into play.

If you look at the racquet MMOI picture above, as the racquet rotates with a mixture of transverse and polar rotation towards the racquet with the racquet aligned at 45 degrees to the extended forearm after ulnar deviation is completed, the racquet tip traces an arc toward the ball.

In the case of my serve with the wrist laid back, the arc is much larger.

I can bring parametric acceleration into play by pulling the butt cap towards the centre of the arc. This gives the following benefits

1. It accelerates the racquet head even further
2. It gives a larger "high point", where the racquet head is accelerating but not closing so fast. This gives me better control in timing the stroke, aiming for sweetspot etc.

In the traditional serve I cannot bring parametric acceleration into play because the wrist is not laid back and obstructs any pulling and the arc is smaller giving much less time to bring it into play. I am working on some adjustments to make it possible in a traditional serve, but they are works in progress.
You are failing completely in terms of presentation because you do not define
parametric acceleration for serve
The definition for golf does not help
 
Thanks, I was referring to hitting flat first serves, not spin, not kick first serves.

If you need a high bouncing flat, you will need a high angle of incidence. So you have to somehow get the ball to land short and start from higher up. That is a function of contact height and face angle. Karlovic and Isner can do it. If get my timing right for high vertical leg drive serves it works. The view from up there is nice. But is works so rarely and I need fresh legs.
 
You are failing completely in terms of presentation because you do not define
parametric acceleration for serve
The definition for golf does not help

It was found that, for amass rotating around a pivot, if the pivot is moved in the direction opposite to the direction of centrifugal force of the mass, the kinetic energy of the mass could be increased.The increase is a result of the mutual action of the two governing factors of the system, which are the centripetal force and the pull velocity. A special type of equation of motion governs this phenomenon. second_derivative(theta) + epsilon sin(theta) = 0, and the parameter in the second term of the left-hand side of the equation epsilon characterizes its behavior.

https://www.researchgate.net/public..._inward_pull_of_the_golf_club_at_impact_stage

In the case of the the tennis serve during approach to contact in both traditional and my low bouncing serve, the tennis racquet

KtaOaGL.png


is rotating a transversely and along the polar axis around the grip pivot towards the tennis ball. Pull on the grip pivot (which is close to the butt cap in my serve and I assume is pretty close to that for other servers) in the direction opposite to centrifugal force of mass (somewhere towards the top left of the opponents court to around the net maybe - hard to tell exactly it happens so fast) will cause this acceleration.
 
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julian

Hall of Fame
It was found that, for amass rotating around a pivot, if the pivot is moved in the direction opposite to the direction of centrifugal force of the mass, the kinetic energy of the mass could be increased.The increase is a result of the mutual action of the two governing factors of the system, which are the centripetal force and the pull velocity. A special type of equation of motion governs this phenomenon. theta + epsilon sin(theta) = 0, and the parameter in the second term of the left-hand side of the equation epsilon characterizes its behavior.

https://www.researchgate.net/public..._inward_pull_of_the_golf_club_at_impact_stage

In the case of the the tennis serve during approach to contact in both traditional and my low bouncing serve, the tennis racquet

KtaOaGL.png


is rotating a transversely and along the polar axis around the grip pivot towards the tennis ball. Pull on the grip pivot (which is close to the butt cap in my serve and I assume is pretty close to that for other servers) in the direction opposite to centrifugal force of mass (somewhere towards the top left of the opponents court to around the net maybe - hard to tell exactly it happens so fast) will cause this acceleration.
Please note that you did not define theta
 

julian

Hall of Fame
It was found that, for amass rotating around a pivot, if the pivot is moved in the direction opposite to the direction of centrifugal force of the mass, the kinetic energy of the mass could be increased.The increase is a result of the mutual action of the two governing factors of the system, which are the centripetal force and the pull velocity. A special type of equation of motion governs this phenomenon. theta + epsilon sin(theta) = 0, and the parameter in the second term of the left-hand side of the equation epsilon characterizes its behavior.

https://www.researchgate.net/public..._inward_pull_of_the_golf_club_at_impact_stage

In the case of the the tennis serve during approach to contact in both traditional and my low bouncing serve, the tennis racquet

KtaOaGL.png


is rotating a transversely and along the polar axis around the grip pivot towards the tennis ball. Pull on the grip pivot (which is close to the butt cap in my serve and I assume is pretty close to that for other servers) in the direction opposite to centrifugal force of mass (somewhere towards the top left of the opponents court to around the net maybe - hard to tell exactly it happens so fast) will cause this acceleration.
Researchgate.net has the related article by Nsbit and McGinnis of 2014 for golf
 
Please see that the symbol of the second derivative of theta is missing
Please note that you did not define theta

It is a quick tug right before contact after a 180 degree extreme wrist lag pull to the ball. So 180 degrees I guess. 180 degrees is only possible with a wrist laid out serve like mine. Doesn't seem to depend on the force of the tug but on how quick it is like the paper says. It does not take much effort at all. Just timing.

The animated gif above does not show it. That video was before I discovered this effect.
 

Chas Tennis

G.O.A.T.
............. The argument seems to be that since it is much more easier to move the racquet laterally and to spin it along the polar axis than it is to rotate it transversely, much more RHS is generated by a traditional serve than a serve like mine which has a large transverse rotation component.

KtaOaGL.png


This argument has a number of fallacies

  1. In a traditional serve most of the RHS at release past big L is generated through ISR with the racquet at a 45 degree angle to the forearm. So it has the same transverse rotation component as my serve (but half as much) and this transverse component is the largest determiner of RHS in this serve.
  2. It ignores a two big determiners of final RHS which are the angular deviations involved (twice as much in my case) and the rotational power stored and released (which is much larger in my case).
..................................................

Do you have some references on this argument, who said what?
 

Raul_SJ

G.O.A.T.
As you can see in frame one above I have a large plant angle and from the first video you can see my front foot, shuffling, planting and forcefully pushing down and generating a large ground force impulse in the time period between maximal elbow raise in frame 2 and maximum ISR stretch in frame 3.

I take it that the "front foot plant angle" refers to how far the feet are apart. The usual coaching advice is to have feet shoulder-width apart with a platform stance serve. Cricket bowlers are allowed a running start so it is unclear if that cricket stance offers any advantage to servers. I don't think I've seen any pros with feet that far apart. I will experiment with this stance...

Also note that the front foot lands backward instead of landing forward. Roscoe Tanner's front foot also appears to land forward. This backward landing looks like it will result in a loss of power as the weight is not shifted forward.
 
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I take it that the "front foot plant angle" refers to how far the feet are apart. The usual coaching advice is to have feet shoulder-width apart with a platform stance serve. Cricket bowlers are allowed a running start so it is unclear if that cricket stance offers any advantage to servers. I don't think I've seen any pros with feet that far apart. I will experiment with this stance...

Also note that the front foot lands backward instead of the common landing forward. This backward landing looks like it will result in a loss of power as the weight is not shifted forward.

Baseball pitchers have a large plant angle as well. They don't have a running start.

http://lermagazine.com/article/influence-of-stride-length-on-mechanics-of-pitching

This angle won't help you unless you are using the foot plant to put a brake on the rotation of your trunk and convert that inertia into a shoulder stretch.

The foot landing backward is not typical. Usually ball is tossed well into the court with this kind of serve. Preserving ground impulse as long as possible does not mean that you cannot use your height in other ways like reducing the ball travel distance to the net, thus reducing the contact height needed to safely clear the net.
 

julian

Hall of Fame
It was found that, for amass rotating around a pivot, if the pivot is moved in the direction opposite to the direction of centrifugal force of the mass, the kinetic energy of the mass could be increased.The increase is a result of the mutual action of the two governing factors of the system, which are the centripetal force and the pull velocity. A special type of equation of motion governs this phenomenon. second_derivative(theta) + epsilon sin(theta) = 0, and the parameter in the second term of the left-hand side of the equation epsilon characterizes its behavior.

https://www.researchgate.net/public..._inward_pull_of_the_golf_club_at_impact_stage

In the case of the the tennis serve during approach to contact in both traditional and my low bouncing serve, the tennis racquet

KtaOaGL.png


is rotating a transversely and along the polar axis around the grip pivot towards the tennis ball. Pull on the grip pivot (which is close to the butt cap in my serve and I assume is pretty close to that for other servers) in the direction opposite to centrifugal force of mass (somewhere towards the top left of the opponents court to around the net maybe - hard to tell exactly it happens so fast) will cause this acceleration.
You should write epsilon*sin(theta) instead of dropping the multiplication symbol *
The way the equation is written now is incorrect because it is not an equation right
now in the first place
Your sentences are too long - I cannot understand the last sentence of the post
 

julian

Hall of Fame
Baseball pitchers have a large plant angle as well. They don't have a running start.

http://lermagazine.com/article/influence-of-stride-length-on-mechanics-of-pitching

This angle won't help you unless you are using the foot plant to put a brake on the rotation of your trunk and convert that inertia into a shoulder stretch.

The foot landing backward is not typical. Usually ball is tossed well into the court with this kind of serve. Preserving ground impulse as long as possible does not mean that you cannot use your height in other ways like reducing the ball travel distance to the net, thus reducing the contact height needed to safely clear the net.
Try to split the last sentence into two
Reading your posts blows a brain of a reader

The concept of landing backward is not very easy to defend
(assuming that you promote it one way or another).

The basic tenant of modern serve is to combine two momenta of a body-
forward and upward.
These two momenta translate somehow into the racket head speed via the kinetic chain
Julian W.Mielniczuk
 
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