Please recommend a poly that just grabs the "bleep" out of the ball

[Karma Tennis]

lol u took the top 3 players in the game who are basically superhuman...what about all the college players that use shaped strings successfully...?

How many US College Players actually use shaped strings by choice? Afaik, most of them simply use the string they are provided with. This is usually the string the Coaches select, the string that is provided by a Sponsor, or the cheapest string.

Anyway, the top 3 players would be the Gold Standard. If they don't see any real benefit out of it, then anyone else is probably benefiting from a Placebo effect of sorts.

Think about it. If your stroke technique alone generates 1000 RPM, the best string with snapback is probably going to enhance it by a max of about 25% and that is at the extreme end of the scale.

Is there really that big of a difference at Club and College level between 1000 and 1250? I dunno. I guess some probably feel better thinking about that extra 250 RPMs. But from a scientific perspective, the Magnus Effect really isn't that much greater.

Perhaps if you a generating 3000RPM. The additional 600 RPM would make a difference. But how many players are consistently generating 3000 RPM from stroke to stroke?

Things are very different in the real world, compared to what is going on in most player heads. LOL.

You're also talking about three players who are very far into their careers, who have also shown significant resistance to change anything and are set in their ways.

I don't agree with this. The Top players are always experimenting with their equipment. At the level they are playing at, even a minor improvement can translate to a significant victory.

And in spite of all the "Mail" that is provided about the Top players' equipment. Truth is, very few people really know exactly what the Top players are using at any given moment.

Remember Rafa uses RPM Blast. It is a shaped string. I doubt Rafa would have started his tennis playing career using shaped strings.

Still, as always, YMMV. Different strokes for different folks.

At the end of the day, the most important think is to WIN matches. Anything that helps a given player WIN more matches is the goal, regardless of the reason, fact or fiction.

 

[mikeeeee]

How many US College Players actually use shaped strings by choice? Afaik, most of them simply use the string they are provided with. This is usually the string the Coaches select, the string that is provided by a Sponsor, or the cheapest string.

Anyway, the top 3 players would be the Gold Standard. If they don't see any real benefit out of it, then anyone else is probably benefiting from a Placebo effect of sorts.

Think about it. If your stroke technique alone generates 1000 RPM, the best string with snapback is probably going to enhance it by a max of about 25% and that is at the extreme end of the scale.

Is there really that big of a difference at Club and College level between 1000 and 1250? I dunno. I guess some probably feel better thinking about that extra 250 RPMs. But from a scientific perspective, the Magnus Effect really isn't that much greater.

Perhaps if you a generating 3000RPM. The additional 600 RPM would make a difference. But how many players are consistently generating 3000 RPM from stroke to stroke?

Things are very different in the real world, compared to what is going on in most player heads. LOL.



I don't agree with this. The Top players are always experimenting with their equipment. At the level they are playing at, even a minor improvement can translate to a significant victory.

And in spite of all the "Mail" that is provided about the Top players' equipment. Truth is, very few people really know exactly what the Top players are using at any given moment.

Remember Rafa uses RPM Blast. It is a shaped string. I doubt Rafa would have started his tennis playing career using shaped strings.

Still, as always, YMMV. Different strokes for different folks.

At the end of the day, the most important think is to WIN matches. Anything that helps a given player WIN more matches is the goal, regardless of the reason, fact or fiction.

If I was a college player I would do what most players seemingly do. Use the same strings I had been using. If they provide crap strings to you that don’t work for your game, it’s in everyone’s best interest including the coach to have you use the strings that give you the best chance of winning matches.

Also, when Nadal came on the scene he was using Big Banger Original. Honestly don’t know if that’s shaped but I’m guessing it is due to his swing motion. Idk if he could do what he does with round strings.

 

[Shaolin]

If I was a college player I would do what most players seemingly do. Use the same strings I had been using. If they provide crap strings to you that don’t work for your game, it’s in everyone’s best interest including the coach to have you use the strings that give you the best chance of winning matches.

Also, when Nadal came on the scene he was using Big Banger Original. Honestly don’t know if that’s shaped but I’m guessing it is due to his swing motion. Idk if he could do what he does with round strings.

When Nadal came on the scene he was using Babolat Duralast or Polymono not BBO.

 

[Ronaldo]

Any posts regarding what is more important, a shaped poly or the snapback effect?

 

[blai212]

Any posts regarding what is more important, a shaped poly or the snapback effect?

shaped poly can still provide good snapback. @monfils is my homeboy uses diadem solstice power strung quite low at 40 lbs to promote snapback effect in those star shaped poly strings which I believe is the best at grabbing/biting the ball providing insane spin. What most people arent grasping is that shaped poly provides more spin but also higher launch angle...maybe the people who use round polys aren’t interested in having such a high launch angle and hence don’t use shaped polys cuz they’re not interested in implementing it into their game...


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[Ronaldo]

shaped poly can still provide good snapback. @monfils is my homeboy uses diadem solstice power strung quite low at 40 lbs to promote snapback effect in those star shaped poly strings which I believe is the best at grabbing/biting the ball providing insane spin. What most people arent grasping is that shaped poly provides more spin but also higher launch angle...maybe the people who use round polys aren’t interested in having such a high launch angle and hence don’t use shaped polys cuz they’re not interested in implementing it into their game...


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Experienced playing against players with a steep launch angle and huge spin. Those guys must re-string weekly or more. Need mail gloves to string that often.

 

[Karma Tennis]

If I was a college player I would do what most players seemingly do. Use the same strings I had been using. If they provide crap strings to you that don’t work for your game, it’s in everyone’s best interest including the coach to have you use the strings that give you the best chance of winning matches..

Every US College player I know, and I know a few, use the string they are provided with because it doesn't cost them anything extra.

I think you underestimate the importance of $$$ to College Students.

This tells me two things .... College Students would rather spend their money on things other than tennis strings ... And there isn't really that much of a performance difference at College level between fresh Poly and Synthetic Gut for most students.

 

[Injured Again]

Any posts regarding what is more important, a shaped poly or the snapback effect?

I'm personally not a firm believer of snapback, just because it is hard to reconcile what I see with what is supposed to be happening.

What is supposed to be happening is that as the ball is leaving the strings, the mains that have been displaced spring back and impart spin. The ball is on the strings for a total of 6 milliseconds, so figure about half of that time is the ball reaching maximum compression, and half of that time is the ball rebounding off the strings when this snapback is supposed to occur, a duration of 3 milliseconds. This means the main has to move back into place in 3 milliseconds or faster, a frequency of 333 Hertz or higher.

What I see is that if I take any freshly strung poly and forcibly displace a main with my fingers, then let it snap back, it might return to its original position but at a speed nowhere close to 3 milliseconds. You can actually see the string slide back into position, whereas if you pluck a musical instrument string with a frequency of around 333 Hertz, it vibrates so fast that it is a blur. So if snapback really happens in the 3 milliseconds when a ball is departing the stringbed, I should also see the main really snap back so fast it is a blur. That doesn't happen, and that's why I'm skeptical of snapback being a significant contributor to spin.

 

[Injured Again]

I don't agree with this. The Top players are always experimenting with their equipment. At the level they are playing at, even a minor improvement can translate to a significant victory.

We will just have to agree to disagree. I see someone like Federer continue to shank ball after ball for years before finally switching to a larger frame, and then switch from a tuxedo paint job back to all black, because of what? The paint made it play differently? That just shows to me that there's reluctance and probably superstition in their approach to equipment.

 

[Ronaldo]

We will just have to agree to disagree. I see someone like Federer continue to shank ball after ball for years before finally switching to a larger frame, and then switch from a tuxedo paint job back to all black, because of what? The paint made it play differently? That just shows to me that there's reluctance and probably superstition in their approach to equipment.

Shirley, when day turns into night, lead paint kills

 

[Christoforos Giatzakis]

I'm personally not a firm believer of snapback, just because it is hard to reconcile what I see with what is supposed to be happening.

What is supposed to be happening is that as the ball is leaving the strings, the mains that have been displaced spring back and impart spin. The ball is on the strings for a total of 6 milliseconds, so figure about half of that time is the ball reaching maximum compression, and half of that time is the ball rebounding off the strings when this snapback is supposed to occur, a duration of 3 milliseconds. This means the main has to move back into place in 3 milliseconds or faster, a frequency of 333 Hertz or higher.

What I see is that if I take any freshly strung poly and forcibly displace a main with my fingers, then let it snap back, it might return to its original position but at a speed nowhere close to 3 milliseconds. You can actually see the string slide back into position, whereas if you pluck a musical instrument string with a frequency of around 333 Hertz, it vibrates so fast that it is a blur. So if snapback really happens in the 3 milliseconds when a ball is departing the stringbed, I should also see the main really snap back so fast it is a blur. That doesn't happen, and that's why I'm skeptical of snapback being a significant contributor to spin.

I have a hard time believing this too.
When I displace just strung poly mains with my fingers they don't return back to their original position. The same happens with poly mains played even for as little as an hour. The only time they return to their original position is 24h after stringing and before played for the first time and even then they return slowly...

 

[Karma Tennis]

I have a hard time believing this too.
When I displace just strung poly mains with my fingers they don't return back to their original position. The same happens with poly mains played even for as little as an hour. The only time they return to their original position is 24h after stringing and before played for the first time and even then they return slowly...

Yasou Chris

What racquet are you talking about? What string? And what tension?

We use strings inc. Volkl Cyclone, Solinco Hyper-G, and various cheaper Polys. Typically strung anywhere from 45lbs to 60lbs.

Freshly strung beds always return back to their original position. I tend to string most Poly after about 5 hours of use. But even at the 5 hour mark, the mains are still sliding back to their original straight position.

BTW, you shouldn't be expecting a flick snap back. It is more like a slide back into place.

Remember, when the ball impacts the string bed, both the Main strings and the Cross strings are deflected. The Cross string deflection aids the Main strings to slide out of position around the ball and then return to their original position post ball impact.

Saying all this ... I don't feel that the snap back effect has a significant impact on spin potential unless the player has excellent technique and is a very hard hitter. That would be beyond most Club players. Even then, I think snap back probably increase spin potential by a max. of about 10% for most players.

 

[blai212]

I'm personally not a firm believer of snapback, just because it is hard to reconcile what I see with what is supposed to be happening.

What is supposed to be happening is that as the ball is leaving the strings, the mains that have been displaced spring back and impart spin. The ball is on the strings for a total of 6 milliseconds, so figure about half of that time is the ball reaching maximum compression, and half of that time is the ball rebounding off the strings when this snapback is supposed to occur, a duration of 3 milliseconds. This means the main has to move back into place in 3 milliseconds or faster, a frequency of 333 Hertz or higher.

What I see is that if I take any freshly strung poly and forcibly displace a main with my fingers, then let it snap back, it might return to its original position but at a speed nowhere close to 3 milliseconds. You can actually see the string slide back into position, whereas if you pluck a musical instrument string with a frequency of around 333 Hertz, it vibrates so fast that it is a blur. So if snapback really happens in the 3 milliseconds when a ball is departing the stringbed, I should also see the main really snap back so fast it is a blur. That doesn't happen, and that's why I'm skeptical of snapback being a significant contributor to spin.

i dont know about you but when i hit an extreme spinny shot on my serve or forehand I can hear the strings moving but afterwards upon looking at the string bed, it seems as if the strings have not moved. Unlike synthetic gut, the string bed of the poly will displace back to its original position. If you have slow racquet head speed and/or hit flat, then the snapback of poly is less likely to happen which is why poly is only recommended for advanced players who impart a lot of spin on the ball similar to rafa.


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[blai212]

Every US College player I know, and I know a few, use the string they are provided with because it doesn't cost them anything extra.

I think you underestimate the importance of $$$ to College Students.

This tells me two things .... College Students would rather spend their money on things other than tennis strings ... And there isn't really that much of a performance difference at College level between fresh Poly and Synthetic Gut for most students.

FYI quality poly strings do not cost a fortune...maybe $10/set...and once they get good, they get sponsored so it becomes free but they certainly dont use garbage strings that they dont like simply because it’s free


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[blai212]

I'm personally not a firm believer of snapback, just because it is hard to reconcile what I see with what is supposed to be happening.

What is supposed to be happening is that as the ball is leaving the strings, the mains that have been displaced spring back and impart spin. The ball is on the strings for a total of 6 milliseconds, so figure about half of that time is the ball reaching maximum compression, and half of that time is the ball rebounding off the strings when this snapback is supposed to occur, a duration of 3 milliseconds. This means the main has to move back into place in 3 milliseconds or faster, a frequency of 333 Hertz or higher.

What I see is that if I take any freshly strung poly and forcibly displace a main with my fingers, then let it snap back, it might return to its original position but at a speed nowhere close to 3 milliseconds. You can actually see the string slide back into position, whereas if you pluck a musical instrument string with a frequency of around 333 Hertz, it vibrates so fast that it is a blur. So if snapback really happens in the 3 milliseconds when a ball is departing the stringbed, I should also see the main really snap back so fast it is a blur. That doesn't happen, and that's why I'm skeptical of snapback being a significant contributor to spin.

Surely, u do not believe that when you forcibly displace the main string with your fingers that u are using the same amount of force that advanced tennis players strike the ball with that causes the 3 millisecond snapback...


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[Injured Again]

Surely, u do not believe that when you forcibly displace the main string with your fingers that u are using the same amount of force that advanced tennis players strike the ball with that causes the 3 millisecond snapback...


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In every photo by Crawford and Lindsay where they show the amount of main string displacement caused by hitting a ball, it is an amount I can easily replicate with my fingers, about a half inch of sideways movement. If I then release that string, it slides back into position but over a period of about a tenth of a second, not three-thousandths of a second as would be needed for snapback to be effective.

 

[blai212]

In every photo by Crawford and Lindsay where they show the amount of main string displacement caused by hitting a ball, it is an amount I can easily replicate with my fingers, about a half inch of sideways movement. If I then release that string, it slides back into position but over a period of about a tenth of a second, not three-thousandths of a second as would be needed for snapback to be effective.

hitting the ball to create snapback action of mains is not the same as moving it with your fingers...when advanced players blast the ball, it is violent force impacting the frame. It is similar to a baseball player hitting a baseball with full force. Anyways, I cannot comment on how fast the strings snapback because I do not watch the strings move when I’m playing tennis...i’m watching the ball, the court, my opponent and looking ahead. However, with that being said, I can HEAR the strings moving when I hit with spin but afterwards they seem to be right where they were before...if you don’t believe in snapback action of poly strings then you’re probably not a player that’s supposed to be using poly. :shrug:


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[Kevo]

The snapback effect that occurs when hitting the ball is 3 dimensional. And you don't need a super energetic snapback to add a little extra spin. Just a little push as the ball is leaving the strings will add some additional spin. There is video evidence and data to back the phenomenon, so while it may not be worth getting your hopes up that changing to a slick poly will make you into the next Nadal, it does help a little so might give you a small advantage. The other nice thing about slick polys is that they seem to last a little longer, at least in my anecdotal experience.

 

[Karma Tennis]

FYI quality poly strings do not cost a fortune...maybe $10/set...and once they get good, they get sponsored so it becomes free but they certainly dont use garbage strings that they dont like simply because it’s free

US College Tennis players are never supplied with "Garbage Strings". The strings they do get are good enough to warrant them spending the $10/set on other stuff like "Beer" !!!

 

[Injured Again]

hitting the ball to create snapback action of mains is not the same as moving it with your fingers...when advanced players blast the ball, it is violent force impacting the frame. It is similar to a baseball player hitting a baseball with full force. Anyways, I cannot comment on how fast the strings snapback because I do not watch the strings move when I’m playing tennis...i’m watching the ball, the court, my opponent and looking ahead. However, with that being said, I can HEAR the strings moving when I hit with spin but afterwards they seem to be right where they were before...

I am not asking you to look at the strings when you are hitting the ball. I am saying that when you displace the strings manually in a way that is identical to how they are displaced when hitting a ball, as shown by the Crawford and Lindsay photos, that the strings will move back but viisually and obviously slower than would be effective during a ball rebound event that lasts 3 milliseconds. Just do it on a fresh stringing and you can see this clearly.

if you don’t believe in snapback action of poly strings then you’re probably not a player that’s supposed to be using poly. :shrug:

Hopefully you do not work in any field in which logic is necessary if you think this statement is valid.

 

[blai212]

I am not asking you to look at the strings when you are hitting the ball. I am saying that when you displace the strings manually in a way that is identical to how they are displaced when hitting a ball, as shown by the Crawford and Lindsay photos, that the strings will move back but viisually and obviously slower than would be effective during a ball rebound event that lasts 3 milliseconds. Just do it on a fresh stringing and you can see this clearly.



Hopefully you do not work in any field in which logic is necessary if you think this statement is valid.

please elaborate how you’re supposed to manually displace the strings in a way that is identical to when hitting the ball??? for poly strings to be effective, the player must be able to generate enough racquet head speed. Do you really think you can move the strings with your fingers with the same type of force as an advanced player’s swing speed?


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[Injured Again]

please elaborate how you’re supposed to manually displace the strings in a way that is identical to when hitting the ball??? for poly strings to be effective, the player must be able to generate enough racquet head speed. Do you really think you can move the strings with your fingers with the same type of force as an advanced player’s swing speed?

Put three fingers into consecutive gaps in the middle of the center main and pull towards the side. It's not hard to apply 50 pounds of force and displace the main by at least a half inch or more. If you do this when the racquet is clamped in a stringing machine, you can easily see that even a fresh poly string job does not snap back at anywhere near fast enough to effect a ball that rebounds off the strings in 3 milliseconds.

 

[blai212]

Put three fingers into consecutive gaps in the middle of the center main and pull towards the side. It's not hard to apply 50 pounds of force and displace the main by at least a half inch or more. If you do this when the racquet is clamped in a stringing machine, you can easily see that even a fresh poly string job does not snap back at anywhere near fast enough to effect a ball that rebounds off the strings in 3 milliseconds.

you really must not understand physics, tennis, or both....it is not physically possible to recreate the amount of force an advanced player strikes the ball with your mere fingers unless you have super human strength. Jus think about how much force is impacted on the ball by a racquet swung at full speed to produce 70-80 mph top spin shots.


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[Injured Again]

you really must not understand physics, tennis, or both....it is not physically possible to recreate the amount of force an advanced player strikes the ball with your mere fingers unless you have super human strength. Jus think about how much force is impacted on the ball by a racquet swung at full speed to produce 70-80 mph top spin shots.

I believe I have a good understanding of the physics involved, thank you.

Have a read of this paper by Rod Cross and Crawford Lindsay:

https://pdfs.semanticscholar.org/17...FjAAegQIAxAB&usg=AOvVaw369U-rA05VGNZEhrubBqyY

in particular, look at the last paragraph on page 221, in particular, this text:

Under normal conditions, the strings of a racket
experience a peak transverse force of up to about
1500 N. Such a force, acting on a ball of mass 57 g
over a period of about 5 ms, is required to change
its velocity from +30 m s±1 to ±30 m s±1. The force
is distributed over all the strings, but if one assumes
that the brunt of the force is shared mainly by ®ve
mains and ®ve cross strings, then the peak force on
each string is about 150 N.

30 meters per second is 67 MPH, and it generates a **PEAK** transverse force on a string of 150 Newtons.

So let's assume the incoming and outgoing balls are faster than 67 MPH, and **DOUBLE** the peak transverse force to 300 Newtons. 300 Newtons is about 67.5 pounds of force.

I don't think it takes superhuman strength, as you claim, to pull on a string with 67.5 pounds of force using three fingers, or humans could never hang their body weight from their fingers. It is a force you should be able to easily generate to see how much displacement it creates in a main string, and how slowly that string moves back to its original position, which by the way is way slower than necessary to snap back before a ball rebounds off the stringbed in 3 milliseconds.

 

[Karma Tennis]

it is not physically possible to recreate the amount of force an advanced player strikes the ball with your mere fingers unless you have super human strength. Jus think about how much force is impacted on the ball by a racquet swung at full speed to produce 70-80 mph top spin shots.

We are talking about a tennis ball here ... not a cricket ball or a baseball.

A regular yellow tennis ball is soft.

 

[blai212]

I believe I have a good understanding of the physics involved, thank you.

Have a read of this paper by Rod Cross and Crawford Lindsay:

https://pdfs.semanticscholar.org/17...FjAAegQIAxAB&usg=AOvVaw369U-rA05VGNZEhrubBqyY

in particular, look at the last paragraph on page 221, in particular, this text:

Under normal conditions, the strings of a racket
experience a peak transverse force of up to about
1500 N. Such a force, acting on a ball of mass 57 g
over a period of about 5 ms, is required to change
its velocity from +30 m s±1 to ±30 m s±1. The force
is distributed over all the strings, but if one assumes
that the brunt of the force is shared mainly by [emoji2400]ve
mains and [emoji2400]ve cross strings, then the peak force on
each string is about 150 N.

30 meters per second is 67 MPH, and it generates a **PEAK** transverse force on a string of 150 Newtons.

So let's assume the incoming and outgoing balls are faster than 67 MPH, and **DOUBLE** the peak transverse force to 300 Newtons. 300 Newtons is about 67.5 pounds of force.

I don't think it takes superhuman strength, as you claim, to pull on a string with 67.5 pounds of force using three fingers, or humans could never hang their body weight from their fingers. It is a force you should be able to easily generate to see how much displacement it creates in a main string, and how slowly that string moves back to its original position, which by the way is way slower than necessary to snap back before a ball rebounds off the stringbed in 3 milliseconds.

well if you could recreate the same amount of force that the ball strikes with the racquet, how come it’s impossible to generate that same booming sound with your fingers? In any case, the period of time in which the ball strikes the racquet (5ms) is about the time when the string snapback occurs. I think TWU explains it quite well. http://twu.tennis-warehouse.com/learning_center/stringmovementPart2.php

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[Injured Again]

The "booming" sound is irrelevant to the peak force experienced by the string. Have you ever assembled IKEA furniture? You know how you can either push a dowel into a hole with some force, but you can also lightly hammer that same dowel into that same hole? By stating the peak string forces are different because of the booming impact noise is like you are trying to say that the force required to insert the dowel is different because in one you hear the sound of the hammer and in the other you don't. That's not how the physics works.

The sound is the result of the ball impacting the strings, which creates the booming noise. However, the peak forces generated, both in my previous post and in my dowel example here, are the same, and have to the same effect, that being the same amount of string deflection whether the ball hits the string or the string is pulled by your fingers, or whether the dowel is inserted by slowly pressing it or by hammering it in.

Just try it. Pull on main with 67.5 pounds of force and see how fast it moves back into position. See if you think that snapback happens in 3 milliseconds or less. Even in your snapshot above, they don't absolutely declare that snapback happens. They "infer" it which means they believe it happens but apparently have no concrete evidence it does or there would be no need to infer.

And read again what I originally wrote in post 108. I said it is hard to reconcile snapback based on what I see - I don't say it can't or doesn't happen. I've shown you that my understanding of physics involved is correct, and have shown you a simple way to see for yourself.

 

[blai212]

The "booming" sound is irrelevant to the peak force experienced by the string. Have you ever assembled IKEA furniture? You know how you can either push a dowel into a hole with some force, but you can also lightly hammer that same dowel into that same hole? By stating the peak string forces are different because of the booming impact noise is like you are trying to say that the force required to insert the dowel is different because in one you hear the sound of the hammer and in the other you don't. That's not how the physics works.

The sound is the result of the ball impacting the strings, which creates the booming noise. However, the peak forces generated, both in my previous post and in my dowel example here, are the same, and have to the same effect, that being the same amount of string deflection whether the ball hits the string or the string is pulled by your fingers, or whether the dowel is inserted by slowly pressing it or by hammering it in.

Just try it. Pull on main with 67.5 pounds of force and see how fast it moves back into position. See if you think that snapback happens in 3 milliseconds or less. Even in your snapshot above, they don't absolutely declare that snapback happens. They "infer" it which means they believe it happens but apparently have no concrete evidence it does or there would be no need to infer.

And read again what I originally wrote in post 108. I said it is hard to reconcile snapback based on what I see - I don't say it can't or doesn't happen. I've shown you that my understanding of physics involved is correct, and have shown you a simple way to see for yourself.

your article is quite outdated...in any case, I cannot speak on the fact of the snapback occurring in a span of 3ms but I do know that it occurs at the same moment of the ball impacting the strings and I can very clearly hear the ‘TCH’ sound of the strings being displaced when I hit a spin heavy ball but upon examining the racquet afterwards, the strings do not seem to have moved out of place. I play with heavy spin at the 4.0-4.5 level, may I ask what level you play at? Poly is not for those players with slow racquet head speed or flat hitters...would that happen to be you?


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[Injured Again]

your article is quite outdated...in any case, I cannot speak on the fact of the snapback occurring in a span of 3ms but I do know that it occurs at the same moment of the ball impacting the strings and I can very clearly hear the ‘TCH’ sound of the strings being displaced when I hit a spin heavy ball but upon examining the racquet afterwards, the strings do not seem to have moved out of place. I play with heavy spin at the 4.0-4.5 level, may I ask what level you play at? Poly is not for those players with slow racquet head speed or flat hitters...would that happen to be you?

You do realize that the article I linked to is authored by the same scientists whose work is the basis for all of the TWU science, including the article you linked to? That outdated paper was likely the foundation for most everything you read today.

In any case, nothing has changed since 2000 to invalidate that article. Physics has not changed. The ball weighs the same. A MPH and a Newton are the same now as then. Science does become wrong because it is old - the laws of motion describing the flight of a tennis ball are centuries old. If you want to invalidate that article, then please tell what has changed to make those conclusions not applicable any more.

The "tch" sound you hear are the strings becoming displaced when they are pressed heavily against each other during the compression phase of ball contact with probably some component coming from the strings sliding against the ball until that sliding action stops. Frictional forces are greater when two objects are pressed against each other such as when the ball is fully compressed against the strings and they are forced to slide across each other. Take a piece of paper and slide it across the floor. Then, press the paper against the floor and slide it at the same speed. Which case makes more noise?

You can, again, easily perform an experiment to see if the "tch" noise comes from the strings moving back into place. Pull the mains out of place on your racquet and let them slide back into place by themselves. Do you hear this "tch" noise? I bet not.

My skill level has no effect on the science and physics behind any of this. Those would work the same whether I am Joe Beginner or Roger Federer. Did you write to Cross and Lindsey to ask their tennis skill level before you linked their technical article in your post #126?

 

[travlerajm]

I'm personally not a firm believer of snapback, just because it is hard to reconcile what I see with what is supposed to be happening.

What is supposed to be happening is that as the ball is leaving the strings, the mains that have been displaced spring back and impart spin. The ball is on the strings for a total of 6 milliseconds, so figure about half of that time is the ball reaching maximum compression, and half of that time is the ball rebounding off the strings when this snapback is supposed to occur, a duration of 3 milliseconds. This means the main has to move back into place in 3 milliseconds or faster, a frequency of 333 Hertz or higher.

What I see is that if I take any freshly strung poly and forcibly displace a main with my fingers, then let it snap back, it might return to its original position but at a speed nowhere close to 3 milliseconds. You can actually see the string slide back into position, whereas if you pluck a musical instrument string with a frequency of around 333 Hertz, it vibrates so fast that it is a blur. So if snapback really happens in the 3 milliseconds when a ball is departing the stringbed, I should also see the main really snap back so fast it is a blur. That doesn't happen, and that's why I'm skeptical of snapback being a significant contributor to spin.

Scientific lab tests show that the strings do in fact snap back (and then some) within the 5ms or so period of dwell time. But the snap back itself is not what provides the enhanced spin. As the ball decompresses and its radius between its center of mass and the stringbed increases, its surface in contact with the stringbed begins to move upward faster than the stringbed as a whole is moving upward, due to the rotational moment of inertia. If the main strings are free to ride upward with the balls surface until the ball leaves the stringbed, then there is less resistance to overspin. This allows the ball’s surface to be moving upward at twice the upward speed of the racquet at the instant when the ball leaves the stringbed.
A stiffer stringbed further enhances this effect by increasing the amount of compression, providing greater potential for overspin.

Conversely, a locked stringbed provides high frictional resistance to overspin, countering the topspin, so that the ball’s surface is only moving slightly faster than the stringbed when it disengages.

 

[Kevo]

Just try it. Pull on main with 67.5 pounds of force and see how fast it moves back into position. See if you think that snapback happens in 3 milliseconds or less. Even in your snapshot above, they don't absolutely declare that snapback happens. They "infer" it which means they believe it happens but apparently have no concrete evidence it does or there would be no need to infer.

So I just restrung one of my frames with Ultra Cable. The broken strings were strung originally, many weeks ago, at 52/36. I restrung it at 52/40. With both the old strings with one broken and the new strings I could not manage to move the strings with my fingers and get my fingers off of the strings before they moved back into place. When I tried to strum it and let my fingers slide off the back it was so uncomfortable I gave that up before I could determine anything useful.

So as far as I can tell they move back as fast as I can move my fingers back. My gut feeling is it's plenty of stored energy to have some effect. I've always said technique is absolutely the most important part of spin, but you can definitely gain enough improvement from a good string to notice the difference between that and an average string.

 

[JOSHL]

So I just restrung one of my frames with Ultra Cannon. The broken strings were strung originally, many weeks ago, at 52/36. I restrung it at 52/40. With both the old strings with one broken and the new strings I could not manage to move the strings with my fingers and get my fingers off of the strings before they moved back into place. When I tried to strum it and let my fingers slide off the back it was so uncomfortable I gave that up before I could determine anything useful.

So as far as I can tell they move back as fast as I can move my fingers back. My gut feeling is it's plenty of stored energy to have some effect. I've always said technique is absolutely the most important part of spin, but you can definitely gain enough improvement from a good string to notice the difference between that and an average string.

You mean Ultra Cable?

 

[Kevo]

You mean Ultra Cable?

Yep. Thanks for pointing that out. Maybe they should release an Ultra Cannon. Sounds like a winner to me.

 

[ron schaap]

How many US College Players actually use shaped strings by choice? Afaik, most of them simply use the string they are provided with. This is usually the string the Coaches select, the string that is provided by a Sponsor, or the cheapest string.

Anyway, the top 3 players would be the Gold Standard. If they don't see any real benefit out of it, then anyone else is probably benefiting from a Placebo effect of sorts.

Think about it. If your stroke technique alone generates 1000 RPM, the best string with snapback is probably going to enhance it by a max of about 25% and that is at the extreme end of the scale.

Is there really that big of a difference at Club and College level between 1000 and 1250? I dunno. I guess some probably feel better thinking about that extra 250 RPMs. But from a scientific perspective, the Magnus Effect really isn't that much greater.

Perhaps if you a generating 3000RPM. The additional 600 RPM would make a difference. But how many players are consistently generating 3000 RPM from stroke to stroke?

Things are very different in the real world, compared to what is going on in most player heads. LOL.



I don't agree with this. The Top players are always experimenting with their equipment. At the level they are playing at, even a minor improvement can translate to a significant victory.

And in spite of all the "Mail" that is provided about the Top players' equipment. Truth is, very few people really know exactly what the Top players are using at any given moment.

Remember Rafa uses RPM Blast. It is a shaped string. I doubt Rafa would have started his tennis playing career using shaped strings.

Still, as always, YMMV. Different strokes for different folks.

At the end of the day, the most important think is to WIN matches. Anything that helps a given player WIN more matches is the goal, regardless of the reason, fact or fiction.

Its no coincidence Stan, Thiem and Nadal all play shaped strings and beat nearly everybody on Rolad Garros. Nadal even became12th time winner. Only in the beginning of his career he used round strings because the shaped were not as good as they are now.

 

[Sean Sullivan]

There may also be something slightly different going on when you're talking about high speed, real time deformation of the strings upon hitting a tennis ball with high spin at 70-90mph as compared to a manual deflection of the strings to the same degree using force "by hand". Watching a slow motion groundstroke, you can see the racquet bend, twist, and reverberate as if it were made of some rubber/liquid hybrid - and if you tried to apply the same deformation on the frame itself strictly using manual forces "by hand", the frame would just snap - while quite strangely being able to handle this deformation repeatedly on end during real time impacts. In this same way, the string bed materials may deform, stretch, liquify, rebound and act in a similar manner to the seemingly "solid" racquet frame at full speed impacts and can't be assumed to be acting with the properties that they have when simply pulled off to the side slowly by hand.

I guess it's hard to quantify, but "duration of applied force" has something to do with the amount of force and deformation a "solid" material can withstand and it's properties may greatly differ while under large forces of very short duration. Watching slow-mo videos of ballistics gelatin getting shot, people's own bones bending like a racquet frames during athletics, etc. can make you reconsider what the "rules" for things we likely oversimplify by considering them "solid" really are.

 

[Injured Again]

Scientific lab tests show that the strings do in fact snap back (and then some) within the 5ms or so period of dwell time. But the snap back itself is not what provides the enhanced spin. As the ball decompresses and its radius between its center of mass and the stringbed increases, its surface in contact with the stringbed begins to move upward faster than the stringbed as a whole is moving upward, due to the rotational moment of inertia. If the main strings are free to ride upward with the balls surface until the ball leaves the stringbed, then there is less resistance to overspin. This allows the ball’s surface to be moving upward at twice the upward speed of the racquet at the instant when the ball leaves the stringbed.
A stiffer stringbed further enhances this effect by increasing the amount of compression, providing greater potential for overspin.

Conversely, a locked stringbed provides high frictional resistance to overspin, countering the topspin, so that the ball’s surface is only moving slightly faster than the stringbed when it disengages.

Do you have a link to a paper or source that conclusively shows snapback occurs? Because it's not 5 ms that the snap back needs to occur in, but half that period, only during the ball rebound phase.

There are additional observations behind my skepticism. The snapback force works via string tension, but only as the sine of the angle of deflection. It's not a large force and then must overcome inter-string friction at every cross over a very short duration for snapback. You can observationally see how small this snapback force is If you have your own stringer, as I do. When you string just the mains, it is very easy to pull a main string so it touches an adjacent string, and then to hold it there against the force that would cause snapback - this takes only a few pounds of force. However, once the crosses are installed, it takes multiple times more force to cause the same amount of deflection, and this is primaily the result of friction at the string intersections. So that small snapback force that is felt when the crosses are not installed is now supposed to quickly and forcefully snap the main back against the large frictional force from the crosses AND also impart rotational energy to the ball?

Can you explain how that would happen? Because physics and mechanics says that the speed a rebound happens depends on the proportion of the rebounding force to the mass causing the resistance. For instance, if you have a spring with a 10 in-lb spring rate and put a 9 pound ball on it, It's going to rebound very slowly compared to if there is a one pound ball. But you can feel the force causing snapback is small by pulling on a tensioned main when the crosses are not installed. How do you reconcile that?

 

[Karma Tennis]

that conclusively shows snapback occurs?

Presumably you are talking about whether string snapback has any impact on ball spin rates?

String snapback definitely occurs. The strings spread apart during ball impact and return to their original position (or reasonably close to it) sometime after the ball has left the string bed.

The higher the force of the ball-stringbed impact the further the springs spread apart.

 

[Injured Again]

There may also be something slightly different going on when you're talking about high speed, real time deformation of the strings upon hitting a tennis ball with high spin at 70-90mph as compared to a manual deflection of the strings to the same degree using force "by hand". Watching a slow motion groundstroke, you can see the racquet bend, twist, and reverberate as if it were made of some rubber/liquid hybrid - and if you tried to apply the same deformation on the frame itself strictly using manual forces "by hand", the frame would just snap - while quite strangely being able to handle this deformation repeatedly on end during real time impacts. In this same way, the string bed materials may deform, stretch, liquify, rebound and act in a similar manner to the seemingly "solid" racquet frame at full speed impacts and can't be assumed to be acting with the properties that they have when simply pulled off to the side slowly by hand.

I guess it's hard to quantify, but "duration of applied force" has something to do with the amount of force and deformation a "solid" material can withstand and it's properties may greatly differ while under large forces of very short duration. Watching slow-mo videos of ballistics gelatin getting shot, people's own bones bending like a racquet frames during athletics, etc. can make you reconsider what the "rules" for things we likely oversimplify by considering them "solid" really are.

This is not how materials work. If materials behaved as you say, we would never be able to design anything like a tennis racquet without making millions of actual physical samples and then testing them all under all possible strains they might encounter.

 

[Injured Again]

Presumably you are talking about whether string snapback has any impact on ball spin rates?

String snapback definitely occurs. The strings spread apart during ball impact and return to their original position (or reasonably close to it) sometime after the ball has left the string bed.

The higher the force of the ball-stringbed impact the further the springs spread apart.

Yes, I wasn't clear. I'm talking about snapback occurring while the ball is still in contact with the strings, so that the ball could get additional spin from the effect.

But if snapback takes so long to occur that it happens when the ball is long gone, is it still "snap" back or is it "slide" back?

 

[bleno567]

US College Tennis players are never supplied with "Garbage Strings". The strings they do get are good enough to warrant them spending the $10/set on other stuff like "Beer" !!!

Being a former D1 US College Tennis player, I can say a few things:

1) We did get a say in what strings we were given. We might not always have gotten what we wanted (e.g. tough luck if you want Lux BB ALU), but you could definitely score the budget version of Luxilon -- not even sure if they still make that stuff (which I always hated)

2) I managed to score my preferred string at the time (pro red code) from the school on a number of occasions.

3) While I never explicitly asked people from other teams, I'd venture to guess that what their program was willing to spring for was quite different from mine.

 

[Ronaldo]

Being a former D1 US College Tennis player, I can say a few things:

1) We did get a say in what strings we were given. We might not always have gotten what we wanted (e.g. tough luck if you want Lux BB ALU), but you could definitely score the budget version of Luxilon -- not even sure if they still make that stuff (which I always hated)

2) I managed to score my preferred string at the time (pro red code) from the school on a number of occasions.

3) While I never explicitly asked people from other teams, I'd venture to guess that what their program was willing to spring for was quite different from mine.

How often did you re-string?

 

[bleno567]

How often did you re-string?

Since I was playing almost every day and I use a racquet with a 16x18 pattern, I was going through them pretty quickly. I'd guess strings were lasting me about ~3-4 sessions tops before they'd pop. I vaguely recall the cheap Lux strings being really durable so lasting longer.

 

[Ronaldo]

Since I was playing almost every day and I use a racquet with a 16x18 pattern, I was going through them pretty quickly. I'd guess strings were lasting me about ~3-4 sessions tops before they'd pop. I vaguely recall the cheap Lux strings being really durable so lasting longer.

So, you may have the best opinion of whether poly snap back really makes a difference. By using fresh strings.

 

[bleno567]

So, you may have the best opinion of whether poly snap back really makes a difference. By using fresh strings.

This seems like kind of a charged conversation and I don't have a hardline stance on it, but yes, I'd say that it does make a difference.

 

[Ronaldo]

This seems like kind of a charged conversation and I don't have a hardline stance on it, but yes, I'd say that it does make a difference.

Notice my mains notch before breaking. Stringbed locks up, no more sliding.

 

[blai212]

Notice my mains notch before breaking. Stringbed locks up, no more sliding.

the mains can notch up due to sliding across the crosses...i think the stringbed locks up when crosses become notched and dont allow mains to slide


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[Sean Sullivan]

This is not how materials work. If materials behaved as you say, we would never be able to design anything like a tennis racquet without making millions of actual physical samples and then testing them all under all possible strains they might encounter.

Watch:

At about the 0:05 mark, there’s a great example of “this is not how materials work”. Here in slow mo, Fed’s racquet appears to be quite flexible. Now, try to distort your racquet with manual forces (by hand) to the same degree and let me know how it turns out for you. It’s almost as if the racquet has different “tolerable range of distortion” properties under the conditions of a high speed ball impact as compared to say “being placed in a vice and slowly bent”, but yeah, that’s just silly.

All I’m saying is that it’s possible that tennis strings, being less rigid than actual racquets, also distort/rebound to some degree upon real time impact that cannot be properly replicated by simply pushing them to the side slowly and letting go. And, this deformation of strings also has some impact on how spin is imparted to a ball during a full speed groundstroke.

People continue to be perfectly capable of designing things in spite of the fact that they don’t fully understand exactly how they work: aspirin, cloud computing, and tennis equipment being among them.

 

[Ronaldo]

the mains can notch up due to sliding across the crosses...i think the stringbed locks up when crosses become notched and dont allow mains to slide


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Thanks, kevlar mains nxt

 

[blai212]

Thanks, kevlar mains nxt

ive never had any luck using synthetic or multi as crosses...i think smooth round poly crosses work better because they allow the mains to slide for better snapback... some synthetic/multi like head velocity have a coating but it still erodes quite fast. Try using a soft smooth round copoly that maintains tension well as a cross string...there are a lot of low priced ones that work well at a fantastic price point. Personally, I like signum pro poly plasma or yonex poly tour pro. Cheap and effective...cant go wrong with those


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[Sean Sullivan]

For what it’s worth, so far I’ve had my best results with a stiff, shaped poly main with a softer smooth, round poly cross. Currently using Tour Bite 16L mains w Lynx 17 crosses. Still experimenting w crosses bc the lynx doesn’t hold tension as well as I’d like. No complaints about how the TB performs, but a full bed can be a bit harsh on the arm.