Two kinds of Topspin

[FailBetter]

In the last few weeks I noticed that there are two really different kinds of a topspin (FH).

1)
I was producing this kind of spin for the last few years and I think most recreational Players do so:
This has a lots of spin immediately after the Ball leaves the strings you can really see it spinning around.
But after the ball lands on the other side, it doesn't really jumps up or penetrates through the court.

What happens?
--> You try even harder and harder to get a more penetrating, heavier ball. But it does not work.

2)
This one is different. When the Ball leaves the strings its not really spinning that hard. Its almost flying straight for a bit. You may even think: "Oh dear this one is flying directly to the fence"...
But its gaining more and more action as it flies through the air. And magically it dives into the court and after the ball lands on the other side it really explodes of the court!

What happens?
Your Opponent will have lots of trouble, getting pushed back and timing issues.

--> That must be the really heavy ball I was always dreaming of. Unfortunately I can't recreate this every time. But it happens more and more.


Just wanted to ask, if someone had similar experiences?
Though till now I wasn't able to create this kind of shot with the backhand.

 

[Dragy]

When the Ball leaves the strings its not really spinning that hard

Did you mean “arcing”? As no ball gains extra RPM after leaving the strings and before bouncing (well, unless it hits the cord). What you talk about is actually pace+spin combo. When the pace is slow to moderate, the ball arcs a lot, and even more with heavier spin. When racquet head speed is higher (towards the pro-level RHS) both ball speed and RPM can be higher, which creates straighter flightpath for the ball until it loses some pace, and that’s the moment spin takes over and makes the ball dive into the court. Great way to hit the ball when you comfortably get to it. Once again, full body effort (leg drive, torso uncoil) is required, high RHS is key.

 

[FiReFTW]

Just like @Dragy said, many people confuse how the ball gets pulled down and arcs down with how much spin it has, but its not true at all.

There are 2 things that affect the gravity pulling the ball into court

1.Speed of ball
2.Topspin of ball

The less speed the more gravity pulls down the ball
The more topspin the more gravity pulls down the ball

If you bunt the ball extremely slow upward and forward in the air, extremely slowly, so it goes like 1 feet infront of you, you will notice the ball immediately after it leaves the racquet starts arcing down and getting pulled down, and yet it has zero topspin.

So a very slow "moonball" will get pulled down into the court alot, even if it has almost no topspin, but the more topspin it has the more it gets pulled down.

Now the more pace you add to the ball, the less it gets pulled down immediately because the speed of the ball resist the gravitational pull.

So an extremely fast hit ball can have a ton of topspin, and yet the flightpath can be fairly flat and straight till the ball slows down enough that the spin takes over and pulls it down, and in most cases these fast balls have more spin than the slow higher arc balls, hence they get pulled down extremely fast.

Higher arcing balls can also have a ton of spin, it really depends, but in that case the ball must have alot of pace and spin alltogether (watch Nadal hit) so the ball will not curve much but will almost fly somewhat straight and UP for a while and seems like it will hit the backfence, but then dip down quite alot.

 

[zill]

In the last few weeks I noticed that there are two really different kinds of a topspin (FH).

1)
I was producing this kind of spin for the last few years and I think most recreational Players do so:
This has a lots of spin immediately after the Ball leaves the strings you can really see it spinning around.
But after the ball lands on the other side, it doesn't really jumps up or penetrates through the court.

What happens?
--> You try even harder and harder to get a more penetrating, heavier ball. But it does not work.

2)
This one is different. When the Ball leaves the strings its not really spinning that hard. Its almost flying straight for a bit. You may even think: "Oh dear this one is flying directly to the fence"...
But its gaining more and more action as it flies through the air. And magically it dives into the court and after the ball lands on the other side it really explodes of the court!

What happens?
Your Opponent will have lots of trouble, getting pushed back and timing issues.

--> That must be the really heavy ball I was always dreaming of. Unfortunately I can't recreate this every time. But it happens more and more.


Just wanted to ask, if someone had similar experiences?
Though till now I wasn't able to create this kind of shot with the backhand.

I know what you mean. The first is 'fluff' topspin. It comes mainly from brushing the ball upwards without much forwards movement of the racquet.

The latter topspin comes from both brushing/pushing up and forwards movement of the racquet contacting the ball. The string actually does most of the 'work' in generating the rpm. It only comes when the ball struck solidly as opposed to the fluff in 1.

All pros hit the latter. Rafa takes the latter to the extreme!

 

[LeeD]

Fast top with a slight side adds to heaviness...with deep placement.

 

[Kevo]

There are 2 things that affect the gravity pulling the ball into court

1.Speed of ball
2.Topspin of ball

The less speed the more gravity pulls down the ball
The more topspin the more gravity pulls down the ball

Spin affects the flight of a ball by creating an air pressure differential. It's not a gravitational effect as gravity is related to mass, and the ball has the same mass no matter how much it's spinning.

Also, the ball moving slowly doesn't make the gravitational effect larger, it just means the ball can't travel as far in the amount of time it takes it to fall to the court.

I haven't studied the magnus force much, but I'm pretty sure that the speed of the ball through the air factors in to the amount of deflection, and so the speed of a topspin shot will affect the amount of deflection if the rate of spin is held constant. It would be really interesting to see any studies of those variables. If anyone knows of one, it would be appreciated if you could post a link.

My intuition would say that if the ball is traveling faster it would enhance the effect, but it could be that hitting faster just means you are adding more spin and the extra spin is what makes the ball drop faster.

 

[dsb]

Spin is an aerodynamic effect...

When you hit the ball hard, with a lot of spin, the ball has to slow down before the aerodynamics of the spin are noticable.

 

[FiReFTW]

Spin affects the flight of a ball by creating an air pressure differential. It's not a gravitational effect as gravity is related to mass, and the ball has the same mass no matter how much it's spinning.

Also, the ball moving slowly doesn't make the gravitational effect larger, it just means the ball can't travel as far in the amount of time it takes it to fall to the court.

I haven't studied the magnus force much, but I'm pretty sure that the speed of the ball through the air factors in to the amount of deflection, and so the speed of a topspin shot will affect the amount of deflection if the rate of spin is held constant. It would be really interesting to see any studies of those variables. If anyone knows of one, it would be appreciated if you could post a link.

My intuition would say that if the ball is traveling faster it would enhance the effect, but it could be that hitting faster just means you are adding more spin and the extra spin is what makes the ball drop faster.

Doesnt make sense for the sole reason that when you hit alot of spin but not alot of penetration the ball has a big arc and dips down, when you hit an extremely hard ball the ball has quite a straight line before it dips down alot, so the forward force must megate the spin pulling the ball down in my opinion.

 

[sureshs]

In the last few weeks I noticed that there are two really different kinds of a topspin (FH).

1)
I was producing this kind of spin for the last few years and I think most recreational Players do so:
This has a lots of spin immediately after the Ball leaves the strings you can really see it spinning around.
But after the ball lands on the other side, it doesn't really jumps up or penetrates through the court.

What happens?
--> You try even harder and harder to get a more penetrating, heavier ball. But it does not work.

2)
This one is different. When the Ball leaves the strings its not really spinning that hard. Its almost flying straight for a bit. You may even think: "Oh dear this one is flying directly to the fence"...
But its gaining more and more action as it flies through the air. And magically it dives into the court and after the ball lands on the other side it really explodes of the court!

What happens?
Your Opponent will have lots of trouble, getting pushed back and timing issues.

--> That must be the really heavy ball I was always dreaming of. Unfortunately I can't recreate this every time. But it happens more and more.


Just wanted to ask, if someone had similar experiences?
Though till now I wasn't able to create this kind of shot with the backhand.

In case 2, you are saying a ball which had less spin at start acquired more spin later?

Let us see how that could happen. Translational kinetic energy could get converted to rotational kinetic energy as the linear speed decreases (of course sum of both energies is always decreasing due to air friction).

But I cannot see the trigger for that. The only case I have heard of is when spin increases after bounce due to the friction with the ground on certain surfaces. I cannot see the trigger happening due to air friction, and air friction is proportional to velocity or sometimes its square, so it can only decrease with decreasing velocity.

@JohnYandell John, have you ever observed rpm of a ball increasing during the flight of ball?

 

[BallBag]

From wiki, Magnus effect (for a cylinder):

where G the vortex strength is given by

rho is air density, v is velocity, r is radius and omega is angular velocity (spin rate). So the force due to spin is proportional to the speed of the ball. Interestingly, there is no fluffiness term. My guess is that a fluffier object has a bigger effective radius.

Other then in top spin balls you can also see the effect in slice balls. The ball starts out with a flat trajectory and looks like it might go long but then it just stalls and dies on my baseline. If you haven't observed this effect its I believe its because I that happens exclusively against me and no one else but me.

 

[Knox]

I think you discovered the difference between a loop shot (basically a topspin slice) and a topspin drive.

The sweet combination between flat and topspin that produces a ball that both penetrates and dives. Congrats, keep practicing it.

 

[sureshs]

I think you discovered the difference between a loop shot (basically a topspin slice) and a topspin drive.

The sweet combination between flat and topspin that produces a ball that both penetrates and dives. Congrats, keep practicing it.

I have never hear the term topspin slice applied to groundstrokes. Is it even possible?

 

[BallBag]

I don't think there is anything particularly magical going on here. Given the ability to produce a certain amount of raquette head speed (RHS), you can trade producing pace for producing top spin. With more RHS you can have more pace and more spin and the ball gets "heavier". Eventually you hit with enough of both that someone who usually doesn't see that type of ball will accuse you of sorcery.

 

[BallBag]

I have never hear the term topspin slice applied to groundstrokes. Is it even possible?

I believe that its just the Australian term for slice.

 

[Kevo]

From wiki, Magnus effect (for a cylinder):

where G the vortex strength is given by

rho is air density, v is velocity, r is radius and omega is angular velocity (spin rate). So the force due to spin is proportional to the speed of the ball. Interestingly, there is no fluffiness term. My guess is that a fluffier object has a bigger effective radius.

Other then in top spin balls you can also see the effect in slice balls. The ball starts out with a flat trajectory and looks like it might go long but then it just stalls and dies on my baseline. If you haven't observed this effect its I believe its because I that happens exclusively against me and no one else but me.

If I'm reading those equations right, thanks for going to the effort of looking them up and posting them btw, my intuition about the force increasing when the ball is traveling faster is correct. So hitting harder, with good technique, is going to pay off both ways, more spin and more velocity, both of which increase the force driving the ball down.

I have observed the slice effect you're talking about. Not that often, but it can certainly happen like that. Just the right amount of speed an spin and you get a little bit of lift that seems to make the ball take a path that has a slight upward arc and it sort of stalls out like a plane almost. I think it's due to the slice helping to slow the ball as it lifts and getting just enough extra flight time so that gravity can win out right as it gets near the baseline.

I tend to try and hit my slices in a sharp downward line if the ball is high enough. I find those will stick really low to the court with enough pace on them. Very difficult to dig out. Usually the more defensive slices I hit have that more floaty feel to them where they might just fall out of the air at some point.

 

[Dartagnan64]

The less speed the more gravity pulls down the ball
The more topspin the more gravity pulls down the ball

The vector force of gravity is 9.8 m/s/s. You can do nothing to change it. It is a constant. You can add or remove other vector forces to influence the ball and it's rate of descent but you can't make "more" gravity.

A ball with topspin will have a downward vector force applied to it. The racket stroke (flat or upward) will apply both horizontal and potentially vertical vectors of force.

A flat ball hit softly doesn't fall any faster than a flat ball hit hard. It's just the hard hit ball will travel further horizontally before it hits the ground because of the greater horizontal vector of force applied. Both balls will hit the ground at the same time but in different locations assuming spin is equal.

 

[FiReFTW]

The vector force of gravity is 9.8 m/s/s. You can do nothing to change it. It is a constant. You can add or remove other vector forces to influence the ball and it's rate of descent but you can't make "more" gravity.

A ball with topspin will have a downward vector force applied to it. The racket stroke (flat or upward) will apply both horizontal and potentially vertical vectors of force.

A flat ball hit softly doesn't fall any faster than a flat ball hit hard. It's just the hard hit ball will travel further horizontally before it hits the ground because of the greater horizontal vector of force applied. Both balls will hit the ground at the same time but in different locations assuming spin is equal.

Cool

So like i thought, the more horizontal force (pace) the more the ball travels straight before diping down, hence very hard shots seem like they travel relatively flat them dip down the last second.

 

[Curious]

I have never hear the term topspin slice applied to groundstrokes. Is it even possible?

A slicing motion doesnt have to be downward.

 

[Knox]

I have never hear the term topspin slice applied to groundstrokes. Is it even possible?

I made up the term to describe shots where the swing path is like >~75% vertical. Very possible. It's how you hit really good topspin lobs, certain approach shots/ passing shots, loop balls (clay court shot), and side-door shots.

 

[PMChambers]

The vector force of gravity is 9.8 m/s/s. You can do nothing to change it. It is a constant. You can add or remove other vector forces to influence the ball and it's rate of descent but you can't make "more" gravity.

A ball with topspin will have a downward vector force applied to it. The racket stroke (flat or upward) will apply both horizontal and potentially vertical vectors of force.

A flat ball hit softly doesn't fall any faster than a flat ball hit hard. It's just the hard hit ball will travel further horizontally before it hits the ground because of the greater horizontal vector of force applied. Both balls will hit the ground at the same time but in different locations assuming spin is equal.

Gravity is not a constant. It's a function of distance between two masses. However, it's close enough to constant for tennis.
Sorry just being prodantic in case tennis moves into space or low orbit.

 

[Friedman Whip]

I made up the term to describe shots where the swing path is like >~75% vertical. Very possible. It's how you hit really good topspin lobs, certain approach shots/ passing shots, loop balls (clay court shot), and side-door shots.

I don't foresee your term 'topspin slice' gaining universal acceptance.

 

[Knox]

I don't foresee your term 'topspin slice' gaining universal acceptance.

Good for you.

The distinction between a topspin slice and a topspin drive is not trivial. My players understand it. That's all that matters to me.

 

[SystemicAnomaly]

@Curious

I made up the term to describe shots where the swing path is like >~75% vertical. Very possible. It's how you hit really good topspin lobs, certain approach shots/ passing shots, loop balls (clay court shot), and side-door shots.

Slice (or slicing) already has 2 meanings in tennis — one for serves and another for ground strokes. Much too confusing to add a 3rd meaning. Suggest you come up with some other terminology if you wish to gain a wide acceptance.

 

[Dartagnan64]

Gravity is not a constant. It's a function of distance between two masses. However, it's close enough to constant for tennis.
Sorry just being prodantic in case tennis moves into space or low orbit.

The force (9.8 m/s/s) is constant within the earth's gravitational pull. None of us is playing tennis outside of that force.

 

[Dartagnan64]

Good for you.

The distinction between a topspin slice and a topspin drive is not trivial. My players understand it. That's all that matters to me.

I only hit topspin slice in golf. In order to hit it in tennis you would have tossing from outside in across the ball while also swinging low to high. Physically a screwy way to swing. A proper FH comes down through the slot from inside out going it hook spin if anything. If that is what you are referring to then I suggest you call it a topspin draw or hook since that is more technically correct.

But I guess we call Slice serves technically wrong too since they have draw spin on them rather than slice spin.

 

[Shroud]

I notice that hitting the ball as it is falling vs. at the top of the bounce produces more arc

 

[bitcoinoperated]

There can't be two types of actual topspin on the ball but perhaps two different characteristic trajectories.

Hit hard, the dipping effect of the heavy spin may be more noticeable/dominant when the ball has slowed down.

A ball not hit hard with lower spin may have lost many of it's rpm nearer the end of the ball flight.

 

[PMChambers]

The force (9.8 m/s/s) is constant within the earth's gravitational pull. None of us is playing tennis outside of that force.

Gavity isn't a constant.

Standard models predict a minimum gravitational acceleration of 9.7803 metres per second squared at the equator and 9.8322 m/s2at the poles. Hirt’s model pinpoints unexpected locations with more extreme differences. Mount Nevado Huascarán in Peru has the lowest gravitational acceleration, at 9.7639 m/s2, while the highest is at the surface of the Arctic Ocean, at 9.8337 m/s2.

 

[Knox]

@Curious


Slice (or slicing) already has 2 meanings in tennis — one for serves and another for ground strokes. Much too confusing to add a 3rd meaning. Suggest you come up with some other terminology if you wish to gain a wide acceptance.

1.) I don't know where people are getting the idea that I'm interested in getting wide acceptance

2.) I'll accept that it's too confusing when someone I'm training doesn't get it. That hasn't happened so I'm not worried.

 

[Knox]

I only hit topspin slice in golf. In order to hit it in tennis you would have tossing from outside in across the ball while also swinging low to high. Physically a screwy way to swing. A proper FH comes down through the slot from inside out going it hook spin if anything. If that is what you are referring to then I suggest you call it a topspin draw or hook since that is more technically correct.

But I guess we call Slice serves technically wrong too since they have draw spin on them rather than slice spin.

You're mixing golf spin terminology with tennis. Slice in tennis is not the same as slice in golf.

 

[Kevo]

A flat ball hit softly doesn't fall any faster than a flat ball hit hard. It's just the hard hit ball will travel further horizontally before it hits the ground because of the greater horizontal vector of force applied. Both balls will hit the ground at the same time but in different locations assuming spin is equal.

If they both have equal topspin and all else is equal but speed, the harder hit ball will hit the ground sooner according to the equations. Speed is multiplied into the final force value.

 

[bitcoinoperated]

Gavity isn't a constant.

Standard models predict a minimum gravitational acceleration of 9.7803 metres per second squared at the equator and 9.8322 m/s2at the poles. Hirt’s model pinpoints unexpected locations with more extreme differences. Mount Nevado Huascarán in Peru has the lowest gravitational acceleration, at 9.7639 m/s2, while the highest is at the surface of the Arctic Ocean, at 9.8337 m/s2.

Only on TTW can be be having a totally useless irrelevant discussion like this.

 

[PMChambers]

Only on TTW can be be having a totally useless irrelevant discussion like this.

No, this is a high school physics discussion. You have lots of useless discussions at school as well. Maybe it's changed since I was last there, been a while.

 

[Morch Us]

I definitely do not want to get into a detailed discussion on this, since it is confusing as hell. At top levels players do use cross strings to create additional spin components along with the regular main strings spin component (which is what most 4.0/4.5 or rec players refer to as topspin), specifically to control the travelling path of the ball and to determine which direction the ball should go after bounce. An example: ball swinging towards left on the air (because of spin) does not necessarily has to always go left after bounce, or even has to go increasingly towards left even on air before bounce. There are mutually "cumulative" components and mutually "distructive" components based on how you hit it. The more travel time through air, the components cumulate or distruct each other more, leading to the final effect. Anyway it is complicated, and most rec players will do fine without worrying about it.

In the last few weeks I noticed that there are two really different kinds of a topspin (FH).

 

[Friedman Whip]

Gavity isn't a constant.

Standard models predict a minimum gravitational acceleration of 9.7803 metres per second squared at the equator and 9.8322 m/s2at the poles. Hirt’s model pinpoints unexpected locations with more extreme differences. Mount Nevado Huascarán in Peru has the lowest gravitational acceleration, at 9.7639 m/s2, while the highest is at the surface of the Arctic Ocean, at 9.8337 m/s2.

I doubt if the force of gravity differs very much from one point on a tennis court to another point about 200 feet away.

 

[Bobby Jr]

Doesnt make sense for the sole reason that when you hit alot of spin but not alot of penetration the ball has a big arc and dips down, when you hit an extremely hard ball the ball has quite a straight line before it dips down alot, so the forward force must megate the spin pulling the ball down in my opinion.

The inertia of a struck ball initially takes it on the path it was struck almost regardless of the spin. As the ball starts to slow the effect of the spin on it becomes more apparent comparatively. That's the reason why people have commented so many times over the years about Federer's forehand sizzle. It doesn't arc quite like a rainbow - it has more linear speed before it dips so it's a much more lop-sided arc shape. Few rec players have the racquet head speed to hit the ball like this - or the timing/string set-up.

This is something Nadal has slowly moved towards doing more in recent years with his forehand. Whereas he once hit more rainbow arc forehands he now hits more lop-sided arc forehands when he's aiming to be more aggressive.

Del Potro is another who hits like this. His forehand seems fairly flat but still has a decent amount of spin which sees the ball do a late dip.

 

[Slicerman]

I think you discovered the difference between a loop shot (basically a topspin slice) and a topspin drive.

The sweet combination between flat and topspin that produces a ball that both penetrates and dives. Congrats, keep practicing it.

wut?

 

[onehandbh]

Gavity isn't a constant.

Standard models predict a minimum gravitational acceleration of 9.7803 metres per second squared at the equator and 9.8322 m/s2at the poles. Hirt’s model pinpoints unexpected locations with more extreme differences. Mount Nevado Huascarán in Peru has the lowest gravitational acceleration, at 9.7639 m/s2, while the highest is at the surface of the Arctic Ocean, at 9.8337 m/s2.

Yes.

I notice this difference when playing on a court oriented North-South. The ball dips noticeably faster on the side closer to one of the poles.

 

[Knox]

wut?

Not all slices are backspin!

 

[slice bh compliment]

Not all slices are backspin!

Right...Some are sidespin.

 

[Knox]

Right...Some are sidespin.

And some are undertopspin. It's when the top of the ball spins upside down.

:,D

 

[StringSnapper]

I believe that its just the Australian term for slice.

Yeah, nah.

 

[Raul_SJ]

Did you mean “arcing”? As no ball gains extra RPM after leaving the strings and before bouncing.

Let's say a Nadal shot is measured at 4000 RPM. That is just after the bounce, correct? What would the RPM typically be just before the bounce? After leaving the strings?

 

[Dragy]

Let's say a Nadal shot is measured at 4000 RPM. That is just after the bounce, correct? What would the RPM typically be just before the bounce? After leaving the strings?

I believe it’s 4000 off the strings. Not betting my fortune though.

 

[Raul_SJ]

I believe it’s 4000 off the strings. Not betting my fortune though.

If it was 4000 RPM off the strings, what would it typically be after the bounce? Could it be more than 4000?

 

[sureshs]

And some are undertopspin. It's when the top of the ball spins upside down.

:,D

What?

 

[hurworld]

If it was 4000 RPM off the strings, what would it typically be after the bounce? Could it be more than 4000?

If the ball spins in the opposite direction of the Earth's rotation, with some physics assumption (conservation of energy, vacuum etc), theoretically, yes

 

[Raul_SJ]

If the ball spins in the opposite direction of the Earth's rotation, with some physics assumption (conservation of energy, vacuum etc), theoretically, yes

I know with 120 mph serve measurements, the speed relates to the ball coming off the strings; it will have about 55 mph horizontal speed after the bounce. With RPM measurements, I assumed it relates to RPM just after the bounce rather than off the strings. Based on the following Riddick serve article, it appears the RPM will increase after the bounce (obviously not nearly as much as on the serve).


Spin
A tennis ball's spin barely decreases during flight, and actually increases when the ball hits the court. "Looking at slow-motion video, you can see that the friction of the court grabs the bottom of the ball, while the top continues to rotate, adding more spin, and converting sidespin into almost pure topspin," says videographer and tennis instructor John Yandell. The average 2400-rpm spin rate Yandell has observed in Roddick's 130-mph serves doubles after the ball hits the court's surface--to a whopping 4800 rpm. This creates the "heavy ball" effect--a shot with so much movement and spin that opponents feel as though they're returning a shot put.

 

[Mongolmike]

None of us is playing tennis outside of that force.

Speak for yourself. Some of my shank shots left Earth's gravity and maybe not even be caught by the Sun's gravitational pull.

Just sayin'

 

[Knox]

What?

If the top of the ball spins upside down underneath the bottom of the ball in a counter rotation to the sides of the ball then that is called 'gotcha'


XD