How can Nadal generate so much spin with his strings not snapping back?

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bad_call

Legend
I think what you mean is the force remains constant but over a larger area. The force/unit area when the area is larger means that it's actually lower.

BP stands (or kneels, sits, crawls, etc) corrected...LOL

btw - it should be happy hour somewhere now. :)
 

tvizz

New User
I agree with Mikeler here, I think shaped/rough strings help spin. Possibly it's the ball pocketing, possibly it reduces friction, possibly it grabs the ball more.

I think string composition is the number one factor though; That shaped strings help, but not a ton.
 

Tonyr1967

Rookie
As they should due to the shaped strings biting into and grabbing the ball better (more friction). That's their intended design to create more spin. More evidence that it's not the snapping back that causes the spin.

Could it be that the shaped strings grab the ball and then move with it...snapping back whilst still gripping the ball - and thus creating more spin?

Btw - just because the strings aren't straight, this does not prove that they haven't snapped back - it just proves that they haven't snapped back fully. This could be because they are notched or it could simply be because they are losing elasticity.

If anyone thinks they can hit real topspin without strings moving, they should try lacquering their stringbed. I recall reading about someone trying this because they assumed topspin was a factor of non- moving strings. They subsequently realised it was down to string movement and developed a specific lubricant.
 

Sander001

Hall of Fame
Could it be that the shaped strings grab the ball and then move with it...snapping back whilst still gripping the ball - and thus creating more spin?
Certainly. Not only has it been proven, but it's been measured in many, many strings.

Oh you were asking BP. In this case, be prepared to be bombarded with very hot air.
 

corners

Legend
KeepUsingThatWord.jpg

Post of the year. And perfect response to Breakpoint. This guy has been opposing the snapback theory with pure drivel for years. He doesn't read any of the papers on the topic, doesn't himself look at any of the evidence, doesn't read anyone else's posts, and then makes up his own imaginary evidence. He just keeps repeating the same nonsense. Several times now he's been soundly trounced in debates on this subject, then disappears for a while, presumably to lick his wounds, and finally returns with the same nonsense:

1) Snap back can't provide more spin because the ball is gone before the strings snap back.

2) It's not snap back that provides more spin, but more friction between the ball and strings.

Both of these notions have been repeatedly and definitely falsified by numerous scientists, including TW's own professor, Rod Cross, and a team of researchers that conduct studies for the International Tennis Federation. The evidence that falsifies these two faulty ideas has been published in numerous scientific journals in at least four countries over a period of ten years!

Breakpoint, for the love of god, read the evidence! Seven excellent papers on this subject have been published by TW University alone since the last time you tried to push your BS here. Read them! And don't try to say you have; if you had, you wouldn't be pushing these falsified concepts.
 

BreakPoint

Bionic Poster
I think what you mean is the force remains constant but over a larger area. The force/unit area when the area is larger means that it's actually lower.
No, that's not what I'm saying. I'm saying the force per unit area remains constant. So for example, if the force is 10 lbs./sq. in., that force applies over the entire area regardless of the size of the area. Thus, for every sq. in. of any given area, the force is 10 lbs.
 

BreakPoint

Bionic Poster
I didn't miss it at all, it just doesn't matter. In your brake analogy, the only way the force per area stays the same when you increase the pad size is if the calipers produce more force. That entirely negates the argument.
Yes, that's what I'm saying. The calipers produce the same force per unit area over the entire area of the brake pad, so the bigger the pad, the greater the total frictional force. Those high performance sports cars have calipers that produce a lot of force to stop the car so they use bigger brake pads to increase the frictional force without wearing out smaller brake pads, which would fail sooner.
 

BreakPoint

Bionic Poster
I seem to get the most spin from shaped strings. Maybe it is because they have less surface area and can slide back. I get amused with people claiming you need smooth round strings to get SnapBack and spin.
Or maybe it's because, like I said earlier - shaped strings bite into and the grip the ball better thereby increasing the friction between the strings and the ball so when you swing upwards, you rotate the ball more easily. However, more friction between the ball the strings also means more friction between the strings themselves.
 

pvaudio

Legend
No, that's not what I'm saying. I'm saying the force per unit area remains constant. So for example, if the force is 10 lbs./sq. in., that force applies over the entire area regardless of the size of the area. Thus, for every sq. in. of any given area, the force is 10 lbs.
Um, no. Just..no. The total force is a constant. The force per unit area is not. The force is 10 pounds. 10 psi is not a force, it is pressure. Force per unit area is the definition of a unit of pressure. You cannot increase the area and have the same pressure without increasing the force. You fill up a 16" tire with air at 30psi. That correlates to some area on the inside of the tire where for every sq", 30 pounds of force is being exerted outwards. You take that same volume of air and put it in a 20" tire. The force exerted on the sidewall of the 16" tire is now being exerted on the sidewall of the 20" tire. Force is the same, but the psi of the air in the bigger tire is much lower. Force per unit area does not remain constant regardless of area. That is physically impossible by definition.
 

BreakPoint

Bionic Poster
Post of the year. And perfect response to Breakpoint. This guy has been opposing the snapback theory with pure drivel for years. He doesn't read any of the papers on the topic, doesn't himself look at any of the evidence, doesn't read anyone else's posts, and then makes up his own imaginary evidence. He just keeps repeating the same nonsense. Several times now he's been soundly trounced in debates on this subject, then disappears for a while, presumably to lick his wounds, and finally returns with the same nonsense:

1) Snap back can't provide more spin because the ball is gone before the strings snap back.

2) It's not snap back that provides more spin, but more friction between the ball and strings.

Both of these notions have been repeatedly and definitely falsified by numerous scientists, including TW's own professor, Rod Cross, and a team of researchers that conduct studies for the International Tennis Federation. The evidence that falsifies these two faulty ideas has been published in numerous scientific journals in at least four countries over a period of ten years!

Breakpoint, for the love of god, read the evidence! Seven excellent papers on this subject have been published by TW University alone since the last time you tried to push your BS here. Read them! And don't try to say you have; if you had, you wouldn't be pushing these falsified concepts.
Evidence? Where? Those studies are NOT evidence. No tests have ever been performed under real world real tennis playing conditions on a tennis court, AFAIK. Clamping a stationary racquet and tossing balls gently at a heavily lubricated stringbed does not come remotely close to what happens under real world ball-stringbed collisions when swinging the racquet at a high rate of speed hitting the ball hard, which produce all kinds of forces (both magnitude and direction) on the strings and the ball which are not measured under the laboratory conditions used in those studies. Besides, I've seen those videos, and to my eyes the ball has left the stringbed before the strings fully snap back.

Take a racquet strung with full poly and pull the main strings to the side as far as you can with your fingers. Now time how long it takes for those strings you pulled aside to snap back to their original vertical positions. If it takes more than 3 milliseconds, then the ball has already left the stringbed by the time they fully snap back.

Then ask yourself this - How did Borg produce so much spin with natural gut strung at 80 lbs. in a 65 sq. in. hoop with zero string snap back (and probably zero string movement)?
 

BreakPoint

Bionic Poster
Um, no. Just..no. The total force is a constant. The force per unit area is not. The force is 10 pounds. 10 psi is not a force, it is pressure. Force per unit area is the definition of a unit of pressure. You cannot increase the area and have the same pressure without increasing the force. You fill up a 16" tire with air at 30psi. That correlates to some area on the inside of the tire where for every sq", 30 pounds of force is being exerted outwards. You take that same volume of air and put it in a 20" tire. The force exerted on the sidewall of the 16" tire is now being exerted on the sidewall of the 20" tire. Force is the same, but the psi of the air in the bigger tire is much lower. Force per unit area does not remain constant regardless of area. That is physically impossible by definition.
Of course it can. The total applied force increases or decreases so that for any given area, the force per unit area remains constant. Not physically impossible at all.
 

pvaudio

Legend
Yes, that's what I'm saying. The calipers produce the same force per unit area over the entire area of the brake pad, so the bigger the pad, the greater the total frictional force. Those high performance sports cars have calipers that produce a lot of force to stop the car so they use bigger brake pads to increase the frictional force without wearing out smaller brake pads, which would fail sooner.
No see, now you're just making things up. With all due respect, I don't think you understand what the term frictional force means. Friction is dependent only on force and not area. It cannot be, otherwise objects would either never move, or never stay in place.

One more example here, inspired by me moving in the coming week. You have a cardboard box at rest on carpet which doesn't compress. It is empty, is 1 square yard, and weighs 1 pound. Now, you add in 100lbs of textbooks. You still have the same COF which is the cardboard against the carpet, the same area of 1 square yard, but now that you've increased the force by 100lbs, the force exerted by friction is playing a much higher role. You went from 1lb/sq yd to 101lb/sq yd. If you want to get back to 1lb/sq yd in the original section of carpet, then you need to increase the size of your box to now have an area of 101sq yards. That's a damn big box. By definition, it is just as difficult to move this enormous box (assuming the weight of the box itself doesn't increase) as when it was simply 100lbs of books in the small box. Why? Because even though the pressure caused by adding the books has decreased across any given sq yard, you now have many many many more sq yards of box to move. The force exerted by friction, in your words, the frictional force, is exactly the same. What's changing is the pressure.

In your brake analogy, applying more pressure to a small brake pad will cause it to fail much more quickly than if you apply less pressure to a larger area. The braking force is still the same, but now you can avoid the brakes overheating and being useless. You are thankful that the force per unit area has decreased, because the force exerted by friction in a given area is lower. That means that area is not going to get worn as quickly. You are still applying that same force across the brake pad. Ergo, the frictional force is exactly the same. Surface area matters not, pressure at a given point does. In short, as someone pointed out quite a bit ago: it's because of heat.
 
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Doubles

Legend
I give up, it's just getting ridiculous now.

By no means am I a science person. (Seriously, I hate it, and have a difficult time understanding it beyond a plebeian level). But I feel like I can understand this stuff better than he can.
 

BreakPoint

Bionic Poster
No see, now you're just making things up. With all due respect, I don't think you understand what the term frictional force means. Friction is dependent only on force and not area. It cannot be, otherwise objects would either never move, or never stay in place.

One more example here, inspired by me moving in the coming week. You have a cardboard box at rest on carpet which doesn't compress. It is empty, is 1 square yard, and weighs 1 pound. Now, you add in 100lbs of textbooks. You still have the same COF which is the cardboard against the carpet, the same area of 1 square yard, but now that you've increased the force by 100lbs, the force exerted by friction is playing a much higher role. You went from 1lb/sq yd to 101lb/sq yd. If you want to get back to 1lb/sq yd in the original section of carpet, then you need to increase the size of your box to now have an area of 101sq yards. That's a damn big box. By definition, it is just as difficult to move this enormous box (assuming the weight of the box itself doesn't increase) as when it was simply 100lbs of books in the small box. Why? Because even though the pressure caused by adding the books has decreased across any given sq yard, you now have many many many more sq yards of box to move. The force exerted by friction, in your words, the frictional force, is exactly the same. What's changing is the pressure.

In your brake analogy, applying more pressure to a small brake pad will cause it to fail much more quickly than if you apply less pressure to a larger area. The braking force is still the same, but now you can avoid the brakes overheating and being useless.
The TOTAL frictional force is dependent on area if you maintain the same force per unit area. Anytime something is "per unit area", then the total amount is dependent on the total area.

In your cardboard box example, if you added more books into the bigger box so that you maintain the same force per square inch applied between the box and the carpet, then the total frictional force would be greater with the bigger box.
 

pvaudio

Legend
The TOTAL frictional force is dependent on area if you maintain the same force per unit area. Anytime something is "per unit area", then the total amount is dependent on the total area.

In your cardboard box example, if you added more books into the bigger box so that you maintain the same force per square inch applied between the box and the carpet, then the total frictional force would be greater with the bigger box.
Please just stop; what you're arguing is literally that using shaped strings vs. round ones is violating the laws of nature. In my box analogy, I don't know where the extra books you keep adding in to keep the force per unit area the same are coming from. You can't do that in a tennis racquet after it's strung.
 

Sander001

Hall of Fame
Take a racquet strung with full poly and pull the main strings to the side as far as you can with your fingers. Now time how long it takes for those strings you pulled aside to snap back to their original vertical positions. If it takes more than 3 milliseconds, then the ball has already left the stringbed by the time they fully snap back.
You reject lab tests in lieu of "real conditions" then proceed to talk about pulling string with your fingers and other nonsense. Hilarious.

In another thread you mention you've been involved in many dozens of lawsuits. I am certain one was for the cost of your education and I'm also certain that you were able to win that case; no judge can be this cruel.
 

BreakPoint

Bionic Poster
In your brake analogy, applying more pressure to a small brake pad will cause it to fail much more quickly than if you apply less pressure to a larger area. The braking force is still the same, but now you can avoid the brakes overheating and being useless. You are thankful that the force per unit area has decreased, because the force exerted by friction in a given area is lower. That means that area is not going to get worn as quickly. You are still applying that same force across the brake pad. Ergo, the frictional force is exactly the same. Surface area matters not, pressure at a given point does. In short, as someone pointed out quite a bit ago: it's because of heat.
I think we are saying the same thing but from opposite directions. I'm saying that high performance sports cars need to use bigger brake pads because the frictional force from the calipers on the rotors is so great. If they used smaller pads, they would wear out and fail more quickly from too much frictional force over a small surface area. But with bigger brake pads, the calipers are able to apply a greater frictional force due to having more surface area to spread out that increased force. Thus, surface area matters since with less surface area, you would have to reduce the applied force, thus giving you less total frictional force and stopping power.
 

pvaudio

Legend
By no means am I a science person. (Seriously, I hate it, and have a difficult time understanding it beyond a plebeian level). But I feel like I can understand this stuff better than he can.
See, I love science and math. For me, understanding how stuff works is the coolest thing. Instead of pushing it on someone that doesn't want to learn it, I love being able to explain something using science but in a way that people get. Formulas and diagrams are only useful if the concept clicks, and if it doesn't, then don't bother. Einstein once said "If you can't explain something to a six year old, then you don't understand it." By Einstein's definition, I know nothing :lol:. I like sharing my passion for it especially when applied to my favorite sport, and I don't think I can change that (even though most people couldn't care less). I think that's where people tend to misinterpret my intentions sometimes. :)
 

BreakPoint

Bionic Poster
You reject lab tests in lieu of "real conditions" then proceed to talk about pulling string with your fingers and other nonsense. Hilarious.
That's a quick way to easily find out if it's even possible for the strings to snap back fast enough before the ball leaves the stringbed. The second hand on a watch in a lab doesn't move any slower than the second hand on your watch. But if you want to set up a full laboratory on a tennis court, be my guest. Buy why go through all the trouble to prove something that's so easily provable? I mean, do you really need to set up a lab to prove that you can't run the 100 meter dash in 3 seconds?
 

pvaudio

Legend
I think we are saying the same thing but from opposite directions. I'm saying that high performance sports cars need to use bigger brake pads because the frictional force from the calipers on the rotors is so great. If they used smaller pads, they would wear out and fail more quickly from too much frictional force over a small surface area. But with bigger brake pads, the calipers are able to apply a greater frictional force due to having more surface area to spread out that increased force. Thus, surface area matters since with less surface area, you would have to reduce the applied force, thus giving you less total frictional force and stopping power.
No, again, you just don't understand what you're saying. You are not applying any more force to anything at all. You're not. Frictional force is not going up or down. It's fixed if your calipers are fixed. They move backwards and forwards with the same force regardless of what's attached to them, because the force they apply is dependent only on what's being pumped into them from your brake lines. Your brake lines have absolutely no idea what sort of calipers and pads you're using, so there is no way the force is going up or down. You're distributing the same force over a wider area. That's why they do not wear out. You are just confusing the terms force and force per unit area. I don't know how else to make you see this, but corners stated this two pages ago. I will try this once more. Brakes work by turning rotation into heat. I know that you know this. A massive brake pad and a tiny brake pad will generate the exact same amount of heat on the same rotor with the same caliper. This is the only thing that brakes do. The difference is that the larger pad is not getting as hot in any given area because it's applying the force across more of the rotor rather than in a tiny area. The amount of heat generated when you stamp on the pedal, however, is exactly the same if they stop you the same.
 

Doubles

Legend
See, I love science and math. For me, understanding how stuff works is the coolest thing. Instead of pushing it on someone that doesn't want to learn it, I love being able to explain something using science but in a way that people get. Formulas and diagrams are only useful if the concept clicks, and if it doesn't, then don't bother. Einstein once said "If you can't explain something to a six year old, then you don't understand it." By Einstein's definition, I know nothing :lol:. I like sharing my passion for it especially when applied to my favorite sport, and I don't think I can change that (even though most people couldn't care less). I think that's where people tend to misinterpret my intentions sometimes. :)
I'm quite the opposite. I prefer names and dates to formulas. Because of that, I developed a love for thinking outside of the box, and developed my reading, writing, and critical thinking skills rather than math and science.
 

Chotobaka

Hall of Fame
I am certain Rafa is following the yobbos and all of their theories in this thread. Maybe the fact that he swings his stick with more speed and aggression and has an infinitely more precise swing path has something to do with the fact that he can generate massive spin -- no matter what.

Perhaps people posting here actually get more spin with textured strings. Likely due to their lack of swing speed and other innate talent. This thread has a bigger twit-factor than some of the prolific, self professed string-expert threads. Just when you thought things could not get any dumber. But then again, consider the source.
 

BreakPoint

Bionic Poster
No, again, you just don't understand what you're saying. You are not applying any more force to anything at all. You're not. Frictional force is not going up or down. It's fixed if your calipers are fixed. They move backwards and forwards with the same force regardless of what's attached to them, because the force they apply is dependent only on what's being pumped into them from your brake lines. Your brake lines have absolutely no idea what sort of calipers and pads you're using, so there is no way the force is going up or down. You're distributing the same force over a wider area. That's why they do not wear out. You are just confusing the terms force and force per unit area. I don't know how else to make you see this, but corners stated this two pages ago. I will try this once more. Brakes work by turning rotation into heat. I know that you know this. A massive brake pad and a tiny brake pad will generate the exact same amount of heat on the same rotor with the same caliper. This is the only thing that brakes do. The difference is that the larger pad is not getting as hot in any given area because it's applying the force across more of the rotor rather than in a tiny area. The amount of heat generated when you stamp on the pedal, however, is exactly the same if they stop you the same.
I'm talking about the high performance sports are are designed to apply greater braking force, which is why they need bigger pads. I'm not saying that the force that is applied varies. The amount is by design. But if they could only use smaller brake pads, they would need to design the brakes to apply less force as to not burn out the pads. Get it now?
 

pvaudio

Legend
I'm talking about the high performance sports are are designed to apply greater braking force, which is why they need bigger pads. I'm not saying that the force that is applied varies. The amount is by design. But if they could only use smaller brake pads, they would need to design the brakes to apply less force as to not burn out the pads. Get it now?
Yeah, okay.
 
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Sander001

Hall of Fame
That's a quick way to easily find out if it's even possible for the strings to snap back fast enough before the ball leaves the stringbed. The second hand on a watch in a lab doesn't move any slower than the second hand on your watch. But if you want to set up a full laboratory on a tennis court, be my guest. Buy why go through all the trouble to prove something that's so easily provable? I mean, do you really need to set up a lab to prove that you can't run the 100 meter dash in 3 seconds?
2 false equivalencies in one paragraph. Impressive.
 

BreakPoint

Bionic Poster
2 false equivalencies in one paragraph. Impressive.
Meanwhile, you just pulled the main strings to the side with your fingers and found that it takes much longer than 3 milliseconds for the strings to snap back to their original vertical positions, which is why you're too embarrassed to respond with anything halfway intelligent. OK, we get it.
 

Readers

Professional
what about the force of gravity? Won't heavier strings be more attracted to the ball?

Not to mention the compounded impact of relativity. Faster swing speed increases relative mass, thereby increasing this gravitational effect. This would explain why lead tape works.

LOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOL, now, this, is funny.

BTW, this also makes 10000% more sense than BP's posts.
 
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Sander001

Hall of Fame
Meanwhile, you just pulled the main strings to the side with your fingers and found that it takes much longer than 3 milliseconds for the strings to snap back to their original vertical positions, which is why you're too embarrassed to respond with anything halfway intelligent. OK, we get it.
Who's "we"? You've been on your own as of 35,070 posts ago.

And I think calling you out on your false equivalencies was very intelligent. We [the real "we", not your imagined advocates of BP BS] haven't forgotten but will remember what you tried to slip by us. You're very sneaky, hiding things in plain sight like that, pretty clever, I dare say!

But really, doubling down on your finger pulling exercise? Now we are beginning to see the level of your personal "real world real tennis playing conditions".
 

bad_call

Legend
See, I love science and math. For me, understanding how stuff works is the coolest thing. Instead of pushing it on someone that doesn't want to learn it, I love being able to explain something using science but in a way that people get. Formulas and diagrams are only useful if the concept clicks, and if it doesn't, then don't bother. Einstein once said "If you can't explain something to a six year old, then you don't understand it." By Einstein's definition, I know nothing :lol:. I like sharing my passion for it especially when applied to my favorite sport, and I don't think I can change that (even though most people couldn't care less). I think that's where people tend to misinterpret my intentions sometimes. :)

totally in the same camp here.
 

ben123

Professional
i dont see evidence for anything in this thread. i see people with opinions who argue whos right n thats about it lol. its also rly cool that people who probably never ever rly studied physics accuse the other person for not knowing physics while they dont know **** about it either. rly good

if i were the tw professor id also say strings go dead and write 30pages with funny pictures about strings going dead. first of all nobody will read this stuff n they(tw) know it. not 1 consumer will really read it. n ofc saying strings go dead yes its true !! means costumers should buy more strings which is good for tw! every1 whos rly takin this serious is naive.

n for the snap back theory if u play on clay ud have to change strings every 30min and change strings. bc playin on clay means dirt on the balls n the friction on the strings gets very high rly fast.. ud either cut ur strings after 10min or wash them on court n i never saw any pro do that lol. n by that theory lubricants would make poly never goin dead which is also so ******** and not one pro uses lubricants omg. or whats with the pros using poly/gut hybrids the snapback in those hybrids simply isnt that good (ok i dont play with such hybrids, but thats what i remember) yet murray and many others can play perfectly fine without super snapback isnt that strange?

nobody who plays tennis cares about all of this
the whole thread is just arguing blabla
 

pvaudio

Legend
i dont see evidence for anything in this thread. i see people with opinions who argue whos right n thats about it lol. its also rly cool that people who probably never ever rly studied physics accuse the other person for not knowing physics while they dont know **** about it either. rly good

if i were the tw professor id also say strings go dead and write 30pages with funny pictures about strings going dead. first of all nobody will read this stuff n they(tw) know it. not 1 consumer will really read it. n ofc saying strings go dead yes its true !! means costumers should buy more strings which is good for tw! every1 whos rly takin this serious is naive.

n for the snap back theory if u play on clay ud have to change strings every 30min and change strings. bc playin on clay means dirt on the balls n the friction on the strings gets very high rly fast.. ud either cut ur strings after 10min or wash them on court n i never saw any pro do that lol. n by that theory lubricants would make poly never goin dead which is also so ******** and not one pro uses lubricants omg. or whats with the pros using poly/gut hybrids the snapback in those hybrids simply isnt that good (ok i dont play with such hybrids, but thats what i remember) yet murray and many others can play perfectly fine without super snapback isnt that strange?

nobody who plays tennis cares about all of this
the whole thread is just arguing blabla
You could have just not said anything at all if you aren't interested in discussion.
 

corners

Legend
Evidence? Where? Those studies are NOT evidence. No tests have ever been performed under real world real tennis playing conditions on a tennis court, AFAIK. Clamping a stationary racquet and tossing balls gently at a heavily lubricated stringbed does not come remotely close to what happens under real world ball-stringbed collisions when swinging the racquet at a high rate of speed hitting the ball hard, which produce all kinds of forces (both magnitude and direction) on the strings and the ball which are not measured under the laboratory conditions used in those studies.

Reading your post, it is even more obvious that you have not read the papers. You clearly have no idea what experiments have been done. It's just not OK to dismiss research without even reading it. I mean, it's your life, but you can't expect people to take your views seriously when you are ignoring all the high-quality evidence in published scientific papers.

One example: The bolded section of your post above. TW University has gone well beyond "tossing balls gently" at lubricated stringbeds. In this study, published more than two years ago (Hello!), balls were fired at 47 mph at a variety of different string types in a 16x19 pattern. Spin rates were measured with the strings lubricated and un-lubricated. The results?

For the 16x19 pattern, the spin increased for every string — from 19–58%. Any adverse effects of a lesser ball-to-string coefficient of friction did not overcome the topspin facilitation due to lubrication.

Upthread, and repeatedly in other previous threads, you have argued that copoly strings, or strings in open patterns, generate more spin because of increased ball-string friction. I think everyone can see clearly that these experiments with lubricated strings destroy your argument.

Besides, I've seen those videos, and to my eyes the ball has left the stringbed before the strings fully snap back.

Your eyes are wrong. Every scientist studying this, poring over those videos and analyzing them frame-by-frame, see the same thing: The main strings snap back with plenty of time to impart additional topspin on the bal.

Take a racquet strung with full poly and pull the main strings to the side as far as you can with your fingers. Now time how long it takes for those strings you pulled aside to snap back to their original vertical positions. If it takes more than 3 milliseconds, then the ball has already left the stringbed by the time they fully snap back.

This has been done. Don't take my word for it, here is John Lyons at Wilson talking about string snap back with Tennis.com:

[Tennis.com]: So the big question obviously is: How exactly does this alternative string pattern affect the snap-back effect?

[John Lyons]: It affects it quite a bit. As I alluded to earlier, we spent a lot of time studying high-speed video. We would fire balls at stationary racquets with different patterns—one with a typical 16 by 18 pattern, another with a 16 by 15, both strung with Luxilon Alu Power—and would compare the snap-back. We measured not only the extent of the strings’ deflection—how far they moved—but also the speed at which they deflected and snapped back. (Since we knew that each frame [of high-speed video] was, let’s say, 1/1000ths of a second, and we could measure how far the strings deflected, we were able to calculate distance over time, or their speed.)

And what happens with the 16x15 pattern is that, compared to a 16x18, not only do the strings move a lot further, but they also snap back really violently. It makes sense. With less friction, the strings deflect further, and because they move further out of place, they snap back past their original position. Which increases the amount of rotation that the strings are able to impart on the ball​
.

Then ask yourself this - How did Borg produce so much spin with natural gut strung at 80 lbs. in a 65 sq. in. hoop with zero string snap back (and probably zero string movement)?

He produced topspin through ball/string friction. Of course. What is your point? The majority of spin from any string setup is produced by ball/string friction forces! The mains don't have to snap back, or move at all, to impart topspin. But when the mains do snap back they can impart an additional amount of spin, which physicists call "overspin." Overspin is defined as spin that is above and beyond what can be produced by ball/string friction alone.

The lab evidence is abundantly clear. Borg could have produced 15-25% more topspin if he switched to copoly strings in a pattern open enough for them to slide and snapback freely. And he could have produced 50-100% more had he switched to a spaghetti racquet, where the mains have complete freedom to slide sideways and snap back. The spaghetti racquet being the ultimate version of Wilson's Spin Effect racquets.

Finally, upthread I posted a portion of an interview with Babolat's Lucien Nogues, where he says:

Geometric strings such at Babolat RPM Blast and Pro Hurricane Tour do help with additional spin on the ball but the reason is different than what most people actually think. The additional spin doesn’t come from the strings gripping the ball more, but rather from an octagonal cross section string that allows the main strings to “slide” with less effort over the cross strings, which increases the spin. The spin comes from the movement of the main strings rather than the texture of the string.

To this, you replied:
Who said anything about strings snapping back causing spin? :)

No, he didn't mention snap back. But had you educated yourself on this topic you would know that he doesn't have to. This is because it has been demonstrated in multiple experiments (for example, here and here) that if the main strings slide but fail to snap back, or snap back too late, that a counter-spin torque, called a normal force offset, is created which reduces the amount of topspin.

So Babolat's Nogues states that Babolat RPM Blast provides more spin because the shape of the strings allows them to slide better. They didn't design them this way to reduce topspin. Which means that they designed them to slide and snap back freely and efficiently.


I'm done. For three or four years, Breakpoint, you've failed to educate yourself on this topic. The resources - the journal articles and papers at TW University - are right there for you. Some posters don't have the educational background to read and understand these papers, but you were trained as an engineer, or something, so I know you have the capacity. I can only conclude that yours is a case of willful ignorance. Until you educate yourself on this topic, responding to your posts is a waste of my time, or of anyone's time.
 

Smasher08

Legend
Corners,

In all honesty, you're wasting your time with NoPoint. Add him to your ignore list and be done with it.

Otherwise you're left with an incessant, bloviating barrage of ignorance, straw men, and Aspergers.

Realistically, someone who actually posts 36,000+ times has few social skills to speak of, a rather stunted and unfulfilling life, and probably a very meagre and pitiable existence.

Just leave him to keep on trying to use anecdotal evidence to "refute" objectively valid results. The internet has its share of lonely, obsessed kooks. Some are fixated upon the Zapruder film, others wear tinfoil hats. He's not rational, won't accept any evidence contrary to his favoured positions, and probably detracts from the vast majority of threads he posts in.

Just ignore, and let it be.
 
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mikeler

Moderator
Or maybe it's because, like I said earlier - shaped strings bite into and the grip the ball better thereby increasing the friction between the strings and the ball so when you swing upwards, you rotate the ball more easily. However, more friction between the ball the strings also means more friction between the strings themselves.

I'm not really sure about the theory but I do know what I experience on court. I get more spin from shaped strings. You are right and everybody else is wrong. Carry on and stop talking about cars everybody, I barely know how to put gas in mine. :)
 

BreakPoint

Bionic Poster
Who's "we"? You've been on your own as of 35,070 posts ago.

And I think calling you out on your false equivalencies was very intelligent. We [the real "we", not your imagined advocates of BP BS] haven't forgotten but will remember what you tried to slip by us. You're very sneaky, hiding things in plain sight like that, pretty clever, I dare say!

But really, doubling down on your finger pulling exercise? Now we are beginning to see the level of your personal "real world real tennis playing conditions".
Um...as far as timing how fast the strings snap back to their original vertical positions, do you really think it matters if it's your fingers or a tennis ball that pulls the strings to the side? Displacement is displacement no matter how you achieve it.

Why are you so afraid to try it? Because you don't want to admit that I'm correct? Figures.......
 

BreakPoint

Bionic Poster
I'm done. For three or four years, Breakpoint, you've failed to educate yourself on this topic. The resources - the journal articles and papers at TW University - are right there for you. Some posters don't have the educational background to read and understand these papers, but you were trained as an engineer, or something, so I know you have the capacity. I can only conclude that yours is a case of willful ignorance. Until you educate yourself on this topic, responding to your posts is a waste of my time, or of anyone's time.
And what makes you think those journals and papers are correct? Just because somebody writes a paper that makes it gospel? Every college student writes papers, does that make them all correct? Before Columbus, there were journals and papers that stated unequivocally that the Earth was flat. Were they all correct? Before Copernicus, there were journals and papers that stated unequivocally that the Sun revolved around the Earth. How did that turn out?

Again, a clamped stationary racquet does not begin to replicate all the forces (in magnitude and direction) that the stringbed experiences when you take a huge swing at the ball - a la Nadal. And those videos that show the strings snapping back quicker than normal were heavily lubricated and strung at ultra low tension which is not realistic as no real tennis player could play with such a stringbed and have any control at all over the ball. And if sliding increases spin, ask yourself why no pros lubricate their strings? Don't they want more spin?

Oh, and co-poly strings would not have helped Borg generate more spin. His racquet was too small (65 sq. in.) to allow him to take the kind of swings necessary to take advantage of the poly strings. His stringbed was way too dense with an 18x20 pattern in a tiny hoop to take advantage of the bite on the ball poly offers. And he strung way too tight to make poly useful.
 
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BreakPoint

Bionic Poster
I'm not really sure about the theory but I do know what I experience on court. I get more spin from shaped strings. You are right and everybody else is wrong. Carry on and stop talking about cars everybody, I barely know how to put gas in mine. :)
Thanks. :)

Yeah, before there was poly, back in the dark ages there were plenty of "rough" or '"textured" nylon strings that were made to produce more spin. They worked. Most people got more spin due to the greater friction between the strings and the ball. There was ZERO snap back in those strings. There was so much friction between the strings that they NEVER snapped back on their own. The stringbed would look like a complete crooked mess after an hour of hitting with every string looking like squiggly lines.
 

BreakPoint

Bionic Poster

The forces are not the same but the time it takes for the strings to snap back is the same! Unless you live in The Twilight Zone, one second on your watch is the same as one second on anyone else's watch (since this is not about Einstein's Theory of Special Relativity). Pull the main strings to the side as far as you want. No matter how much or how little you displace them, it will take longer than 3 milliseconds for the strings to snap back to their original vertical positions.
 

Sander001

Hall of Fame
The forces are not the same but the time it takes for the strings to snap back is the same! Unless you live in The Twilight Zone, one second on your watch is the same as one second on anyone else's watch (since this is not about Einstein's Theory of Special Relativity). Pull the main strings to the side as far as you want. No matter how much or how little you displace them, it will take longer than 3 milliseconds for the strings to snap back to their original vertical positions.
This is a put-on, it's got to be.
The cognitive dissonance that dominates your brain is truly astounding.
 

Rabbit

G.O.A.T.
My take on this is that the "snap back" may happen, and it may have some effect on the amount of topspin one produces. But it is in the same category as an open string pattern. It helps, but it won't turn Connors into Borg.

The extra 200 RPMs that Wilson says the 99S creates may be attributed not only to the snap back, but the the uber open string pattern. The snap back may realistically only contribute about 10 RPMs, who knows.

I love the 99S and I love low tensioned poly in it. :)
 

pvaudio

Legend
I just find it astonishing that universities literally around the world have published their findings on this topic in physics journals, and yet people are here arguing that because they can't see it happen, that it doesn't happen.
 

Smasher08

Legend
universities around the world have published their findings on this topic in physics journals, and a few rocket scientists are arguing that because they can't see it happen, that it doesn't happen.

Makes much more sense when you look at it this way.
 
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Smasher08

Legend
The extra 200 RPMs that Wilson says the 99S creates may be attributed not only to the snap back, but the the uber open string pattern.

On the odd chance that you wish to educate yourself, you should try reading about the 99S's design.

Snap back is what led Wilson to the 99S's more open pattern. They are not separate or independent concepts.

Note that the "uber open string pattern" you refer to is caused by a reduction in cross strings only. This is to allow mains to deflect even more than usual and snap back.

All of the 99S's additional spin is therefore due to snap back.
 
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