What weird type of spin does this ball have on it?

[Alejandro Lanza]

What exactly is 'spiral spin'? sounds physics defying

[SystemicAnomaly]

Originally Posted by Alejandro Lanza

What exactly is 'spiral spin'? sounds physics defying

Spiral spin is a z-axis spin. The z-axis would be the axis that is the same direction as the flight of the ball. Think of the type of spin that badminton shuttles and (American) footballs have when they are in flight. Gun barrels are usually rifled so that they impart a spiral spin to the bullet. This spin tends to stabilize the flight of the projectile.

The tennis ball spins that we are most familiar with are perpendicular to the flight of the ball. Topspin and underspin (backspin) are spins around the x-axis. Vertical axis (y-axis) spin would be sidespin (either left sidespin or right sidespin). Since these x-axis and y-axis spins are perpendicular to the flight of the ball, they are subject to the Magnus effect. This effect is what causes the bending in the flight of the ball. Vertical axis spins cause the ball to deviate left or right while x-axis spins cause flight deviations up and down.

Note that there is no Magnus effect for spiral spin -- this type of spin does not cause any flight deviation and, in fact, tends to stabilize the flight (which is why it is imparted to bullets and, sometimes, to arrows). While spiral spin does not create any deviations while the ball is in flight, it does cause a tennis ball to bounce left or right (when it grabs the court). It is spiral spin, and not (vertical-axis) sidespin, the causes a ball to bounce left or right on an (American) twist serve.
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[tank_job]

So is it that Nadal hit the banana shots that curve back into the tramlines when the ball was low, therefore his forehand was swinging right to left at that point, causing the ball to bend in? And Bellucci hit his curve shot off a high Djokovic forehand, therefore his forehand was swinging from left to right at that ponit - so the ball bent in the opposite direction? It worked well for him since he was hitting an inside in forehand, but if he were hitting a running forehand down the line, the curve would have pulled his shot wide.

So if you want to prevent Nadal hitting banana shots against you, hit very wide AND very high to his forehand, so when he swings at it, the curve he'll naturally put on the ball will cause it to bend away from the tramlines, thus he'll hit the ball wide?

[Clay lover]

It's like hitting a reverse serve. You use a semi western grip to try to swing across a high ball, you naturally get that right-left sidespin component if you're lefty.

Nadal's banana shot spins the other way because he utilizes a different technique. It's more of an "inside out swing" should I say. As he extends out to his target the racquet is moving outwards away from his body. This right-to-left motion helps to generate that left-to-right spin. It's more on purpose than a natural thing to do. It is the easiest to do on low balls.

But the scariest thing is he can do it off relatively high balls too. Imagine how much you have to torque your wrist to create that spin on high balls, Nadal's a beast:

http://www.youtube.com/watch?v=XqcTQ0QHmsk

http://www.youtube.com/watch?v=6OlhRjALofY
5:41

[SystemicAnomaly]

Check out this amazing shot by Andy Roddick against Novak Djokovic:

http://www.youtube.com/watch?v=v7gQ-vySQMk&t=20s
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[J_R_B]

Looks like the sideways curvature is mostly a camera angle illusion, but the shot clearly had a ridiculoue amount of topspin with a little sidespin as well.

[SystemicAnomaly]

^ There is more than just a little bit of sidespin on the Nadal and Roddick shots. Yes, with high camera angle, the topspin curvature might be perceived as added sideways curve. But from the court level, we can see that their is at least a moderate amount of side spin (and perhaps just a little bit of spiral spin).

http://www.youtube.com/watch?v=a1mUUd9qP0Y&t=20s
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[J_R_B]

Originally Posted by SystemicAnomaly

^ There is more than just a little bit of sidespin on the Nadal and Roddick shots. Yes, with high camera angle, the topspin curvature might be perceived as added sideways curve. But from the court level, we can see that their is at least a moderate amount of side spin (and perhaps just a little bit of spiral spin).

http://www.youtube.com/watch?v=a1mUUd9qP0Y&t=20s
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I meant the original Belluci shot. I didn't watch the other vids, but in general, Nadal can do things to a tennis ball that no one else in history has done.

[Alejandro Lanza]

Originally Posted by SystemicAnomaly

Spiral spin a z-axis spin. The z-axis would be the axis that is the same direction as the flight of the ball. Think of the type of spin that badminton shuttles and (American) footballs have when they are in flight. Gun barrels are usually rifled so that they impart a spiral spin to the bullet. This spin tends to stabilize the flight of the projectile.

The tennis ball spins that we are most familiar with are perpendicular to the flight of the ball. Topspin and underspin (backspin) are spins around the x-axis. Vertical axis (y-axis) spin would be sidespin (either left sidespin or right sidespin). Since these x-axis and y-axis spins are perpendicular to the flight of the ball, they are subject to the Magnus effect. This effect is what causes the bending in the flight of the ball. Vertical axis spins cause the ball to deviate left or right while x-axis spins cause flight deviations up and down.

Note that there is no Magnus effect for spiral spin -- this type of spin does not cause any flight deviation and, in fact, tends to stabilize the flight (which is why it is imparted to bullets and, sometimes, to arrows). While spiral spin does not create any deviations while the ball is in flight, it does cause a tennis ball to bounce left or right (when it grabs the court). It is spiral spin, and not (vertical-axis) sidespin, the causes a ball to bounce left or right on a(n) (American) twist serve.

Got it, makes sense, thanks!

[LeeD]

Don't get the mystery on the sidespin shots.
They curve, like a curveball, simple.
You can hit forehands that curve left, you can hit forehands that curve right. Just look at JimmyConnors's forehand.

[5263]

Originally Posted by J_R_B

I meant the original Belluci shot. I didn't watch the other vids, but in general, Nadal can do things to a tennis ball that no one else in history has done.

Yes, Rafa does some excellent things with the ball, but they have all been done historically I'm pretty sure.
I have to bring out my former doubles partner who was a Nat'l champ in Squash and/or racketball (played both on Nat'l level).
He could undoubtedly hit more spin than Rafa, often making the ball look more like a Frisbee than a ball. I've never seen anyone spin one like him; and during live points too.
Crazy thing was returning his serve which came at you on an angle 45 degr off the court. I've seen players try to return it and hit the ball solid, nearly 90 degrees in the wrong direction. Truly amazing that guy.

[LeeD]

Geez, where were you when I mentioned I used to play a B player who often hit the ball with sooo much spin that the ball went oval, and HISSED loudly.
And he had the same serve! Short when he wanted it, heading about 45 degrees sideways and hitting the sidefence around NML depth.
Bunch of huge # posters poo poo'ed me, saying it's impossible to make the ball go oval and HISS loudly, because THEY hadn't seen it.
This guy was 6'3", and could absolutely POUND flat first serves. His problem was that he liked to toy with odd spin shots, and could often be beat if the opponent compensated and anticipated the weirdo spins and angles.

[pvaudio]

HOLY ****, that ball at 3:15 should have sued for battery after that serve

[pvaudio]

Originally Posted by SystemicAnomaly

Spiral spin is a z-axis spin. The z-axis would be the axis that is the same direction as the flight of the ball. Think of the type of spin that badminton shuttles and (American) footballs have when they are in flight. Gun barrels are usually rifled so that they impart a spiral spin to the bullet. This spin tends to stabilize the flight of the projectile.

The tennis ball spins that we are most familiar with are perpendicular to the flight of the ball. Topspin and underspin (backspin) are spins around the x-axis. Vertical axis (y-axis) spin would be sidespin (either left sidespin or right sidespin). Since these x-axis and y-axis spins are perpendicular to the flight of the ball, they are subject to the Magnus effect. This effect is what causes the bending in the flight of the ball. Vertical axis spins cause the ball to deviate left or right while x-axis spins cause flight deviations up and down.

Note that there is no Magnus effect for spiral spin -- this type of spin does not cause any flight deviation and, in fact, tends to stabilize the flight (which is why it is imparted to bullets and, sometimes, to arrows). While spiral spin does not create any deviations while the ball is in flight, it does cause a tennis ball to bounce left or right (when it grabs the court). It is spiral spin, and not (vertical-axis) sidespin, the causes a ball to bounce left or right on an (American) twist serve.
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This is true, but hard to visualize because unlike all of your other examples, the object is spherical.

[mntlblok]

Originally Posted by Clay lover

It is the easiest to do on low balls.

But the scariest thing is he can do it off relatively high balls too. Imagine how much you have to torque your wrist to create that spin on high balls, Nadal's a beast:

http://www.youtube.com/watch?v=XqcTQ0QHmsk

http://www.youtube.com/watch?v=6OlhRjALofY
5:41

Whoa. That's scary - and massively impressive. Not sure those top three guys are human.

Kevin

[Funbun]

I've almost always have done this shot on accident on high balls, as a lefty. It's even costed me points, since the ball will sometimes drift sideways off the court when I want to go down the line.

Contrary to what some may think, it doesn't necessarily have to occur because of a mishit.

In practice, you would try to slap a high ball with as much topspin as possible. It's easiest to create spiral spin on high balls, as the racquet will brush the ball at a more extreme, diagonal angle to create the spiral spin and topspin components.

It's served me well against kids who just moonball all the time.

Bellucci apparently picked the right time and right placement to kill that high ball, on the right side of the court, for the lateral error you can get from the ball spinning like that.

[LeeD]

You know all those posts about how to hit a low ball with a western grip?
THAT's how you curve the ball when you're a lefty going DTL passing attempt. You hit the outside of the ball, it curves. It starts wide of the singles court, somewhere in the alley, then curves back inside the singles sidelines.