Does low driver spin cause loss of control?

[nkurz]

There seems to be common belief on this forum that low driver spin results in an uncontrollable ball.  There are a number of different reasons given for this.  The word "knuckleball" is used often to imply that the ball will drift randomly.   There are also people who believe that high backspin helps prevent slices or hooks.   There's the term "simulator bomb", implying that some simulators have incorrect formulas that show low spin drives as going farther than they do in the real world.  And there's the thought that the ball will simply fall out of the air without enough spin.  How much truth is there to these beliefs?  

 

My personal guess is that most of these beliefs are wrong, and that while driver spin can often be less than optimal for carry distance, it doesn't actually result in uncontrollable flight.  An actual knuckleball in baseball is rotating at most at a few dozen RPM, while a low spin drive might still be a hundred times that.  Backspin doesn't actually reduce sideways curvature, and if anything increases it by keeping the ball in the air longer.  Simulators are mostly accurate for carry distances if correctly set up, although roll distances are very hard to predict.  And while low spin can greatly reduce carry distance, this can also be fixed by raising the launch angle.  

 

Thoughts?  Arguments to the contrary?  

 

 

 

 

 

 

[MelloYello]

My understanding has always been that spin creates movement.

 

The vertical spin component counters gravity. The horizontal spin component creates left/right movement. 

 

So all things being equal, if you have less spin, your ball should pretty much always be going straighter. The question is whether it helps you enough in the vertical to continuously lower spin. 

[me05501]

15 minutes ago, MelloYello said:

My understanding has always been that spin creates movement.

 

The vertical spin component counters gravity. The horizontal spin component creates left/right movement. 

 

So all things being equal, if you have less spin, your ball should pretty much always be going straighter. The question is whether it helps you enough in the vertical to continuously lower spin. 

 

 

A ball in flight is only spinning in one direction: backward around its spin axis. The spin axis is almost always tilted a little left or right, which is what can make the ball turn in that direction, but there aren't two different spin forces acting on the ball at the same time. A minor point but an important one. 

 

@nkurz there's an ideal amount of spin for any shot you hit.

 

For an iron into a green you want enough spin to stop the ball close to where it lands without having so much that the shot balloons and doesn't carry. 

 

For a drive you generally want the ball to fly as far as possible and roll out as far as possible. In a vacuum that might mean very little spin but in the real world the ball needs to have a certain amount of spin to stay aloft as long as possible. 

 

Spin also adds stability to the ball's flight. A ball spinning at the proper rate will hold its line better than one with less spin (that knuckleball of lore). 

 

[MelloYello]

1 hour ago, me05501 said:

 

 

A ball in flight is only spinning in one direction: backward around its spin axis. The spin axis is almost always tilted a little left or right, which is what can make the ball turn in that direction, but there aren't two different spin forces acting on the ball at the same time. A minor point but an important one. 

 

 

It's easier to break it up into components which is how it was traditionally described. That aligns better with how people think. Sin and Cos.

 

There's no need to talk Spin Axis when you can just resolve them into separate components and be done with it. From a player's perspective Spin Axis is nice because you just want it to be 0. If you can eliminate any "side-spin" it's the ideal, perfectly-straight ball-flight. It's worth pointing out that you can never really hit it too straight in golf. Straight is always better. 

 

The vertical component creates one effect (lift). The horizontal component creates another effect (maybe we should call it "drift"). That's still easier for people to think about. Then the "Spin Axis" is just a measure of how much accidental mis-alignment you created between face and path. If you can hit a 3-ft fade versus a 3-yd fade or a 30-yd fade, why not? It's always good to minimize curve and be straighter. More control = better.  

 

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Edited May 15, 2023 by MelloYello

[8602081]

Use the spin to control the ball in windy condition..

 

You can hit a draw or fade into the wind..

 

[nkurz]

6 hours ago, me05501 said:

there's an ideal amount of spin for any shot you hit.

...

For a drive you generally want the ball to fly as far as possible and roll out as far as possible. In a vacuum that might mean very little spin but in the real world the ball needs to have a certain amount of spin to stay aloft as long as possible. 

 

This sounds about right.   I might put it as "for any given launch angle there is an ideal amount of backspin that optimizes carry distance and a slightly lower amount of backspin that optimizes total distance including roll".  

 

6 hours ago, me05501 said:

Spin also adds stability to the ball's flight. A ball spinning at the proper rate will hold its line better than one with less spin (that knuckleball of lore). 

 

This is the part I'm not sure about.  I agree that a lower ball will tend to be less affected by the wind, and one way to achieve good distance with a lower ball is to have a lower launch angle with higher spin, but I'm not sure I believe the "stability" argument.  Once you are above (say) 1000 rpm, I can't see how the physics would help the ball hold a straight line.    What do you think happens, and how does it affect the ball flight?  

[Is Golf Fun or Work]

Didn't many of the OEMs increase spin a little on their current products after feedback from tour pros that the ultra low spin drivers were giving them accuracy issues?

[chollier986]

Backspin will help resist axis tilt, thus creating a straighter ball flight.

[nkurz]

1 hour ago, chollier986 said:

Backspin will help resist axis tilt, thus creating a straighter ball flight.

 

I'm not sure which way you mean this.  

 

If by "resist axis tilt" you mean that it will have more angular momentum, and thus the 3D spin axis of a ball with sidespin will have a greater tendency to keep the axis pointing in the same direction even as the ball curves... maybe?  I confess I don't really understand how the spin axis changes during curving ball flight.   Does it stay the same relative to the direction or the ball, or does it stay the same relative to the golfer?  Or somewhere in between?  

 

If instead you mean that the numerical value for spin axis in degrees changes less with greater backspin, I think this is true but potentially misleading.   Yes, the spin axis tilts less for a given amount of horizontal face angle if you increase the backspin.  But the amount the ball curves off line does not decrease.  If anything, it curves more because the ball stays in the air longer.  

 

This is where the approach @MelloYellomentioned about breaking the spin into components is helpful.    While adding backspin does decrease the tilt as measured in degrees, the sidespin component as measured in RPM stays constant, and thus the sideways force remains constant.   While it's true that the ball actually only rotates in a single direction, the mathematical trick of treating the backspin and sidespin components separately is really useful for understanding the ball flight, whereas the spin axis approach can be very misleading.    

 

(I'm pretty sure I'm right that increased backspin never reduces horizontal curvature, but not 100% confident.  If Part 1 was true about the angular momentum changing things, it's possible some other effect comes in.  If anyone knows more, please correct me!)

[chollier986]

44 minutes ago, nkurz said:

 

I'm not sure which way you mean this.  

 

If by "resist axis tilt" you mean that it will have more angular momentum, and thus the 3D spin axis of a ball with sidespin will have a greater tendency to keep the axis pointing in the same direction even as the ball curves... maybe?  I confess I don't really understand how the spin axis changes during curving ball flight.   Does it stay the same relative to the direction or the ball, or does it stay the same relative to the golfer?  Or somewhere in between?  

 

If instead you mean that the numerical value for spin axis in degrees changes less with greater backspin, I think this is true but potentially misleading.   Yes, the spin axis tilts less for a given amount of horizontal face angle if you increase the backspin.  But the amount the ball curves off line does not decrease.  If anything, it curves more because the ball stays in the air longer.  

 

This is where the approach @MelloYellomentioned about breaking the spin into components is helpful.    While adding backspin does decrease the tilt as measured in degrees, the sidespin component as measured in RPM stays constant, and thus the sideways force remains constant.   While it's true that the ball actually only rotates in a single direction, the mathematical trick of treating the backspin and sidespin components separately is really useful for understanding the ball flight, whereas the spin axis approach can be very misleading.    

 

(I'm pretty sure I'm right that increased backspin never reduces horizontal curvature, but not 100% confident.  If Part 1 was true about the angular momentum changing things, it's possible some other effect comes in.  If anyone knows more, please correct me!)

Ok then, perhaps look at this way.  The greater the backspin, the harder it is to impart side spin.  

[Stuart_G]

9 hours ago, chollier986 said:

Backspin will help resist axis tilt, thus creating a straighter ball flight.

7 hours ago, chollier986 said:

Ok then, perhaps look at this way.  The greater the backspin, the harder it is to impart side spin.  

 

No.  That's faulty logic.  The spin axis alone is not an accurate representation of how straight the ball will go or how far it will go offline.   The side and back spin components effect the ball flight independently.   So the same side spin will have (basically) the same horizontal curve even if the spin axis is different.   That's why if you want to understand the effect on the ball flight - it's always better (less confusing) for most to look at the back and side spin numbers than it is the spin axis number.

 

Side spin tells us how it will curve (horizontally).   Back spin (and other aspects of the launch conditions) will tell us how far it will go or how long it will stay in the air to continue that horizontal curvature.   The only universal generalization is that - the farther the ball goes - the more it will continue to go offline.    Other than that, the complexity of the problem makes any other generalization pretty unreliable.

 

 

20 hours ago, nkurz said:

My personal guess is that most of these beliefs are wrong, and that while driver spin can often be less than optimal for carry distance, it doesn't actually result in uncontrollable flight.

 

 

I tend to agree - at least as generalizations go.  Some may have some truth to them but only is very limited contexts.

 

 

[Howard_Jones]

1 hour ago, Stuart_G said:

 

No.  That's faulty logic.  The spin axis alone is not an accurate representation of how straight the ball will go or how far it will go offline.   The side and back spin components effect the ball flight independently.   So the same side spin will have (basically) the same horizontal curve even if the spin axis is different.   That's why if you want to understand the effect on the ball flight - it's always better (less confusing) for most to look at the back and side spin numbers than it is the spin axis number.

 

Side spin tells us how it will curve (horizontally).   Back spin (and other aspects of the launch conditions) will tell us how far it will go or how long it will stay in the air to continue that horizontal curvature.   The only universal generalization is that - the farther the ball goes - the more it will continue to go offline.    Other than that, the complexity of the problem makes any other generalization pretty unreliable.

 

 

 

I tend to agree - at least as generalizations go.  Some may have some truth to them but only is very limited contexts.

 

 

Im on to a large project where im collecting numbers from Flightscope, and its NOT directly related since this tread is about spin axis or side spin vs back spin,  and my charts from this project is meant to find the "optimum" spin value for a certain ball speed and launch angle.

120 mph ball speed and only 7 launch is "bad numbers", and this is really the only starting point (or lower), where we can see that spin can stretch carry, but since high spin levels reduces roll out as much as it does, even with only 120 ball speed and 7 launch, MY conclusion is that more than 3000 rpm spin is NOT beneficial for this player either.

I will not "jump to conclusion" for what it looks like when im done for all relevant ball speeds up to 200 mph, but i have a feeling that there IS a "golden number" for spin thats "good for all", and it seems to be about 2100 rpm, who actually is enough spin for 120 - 7* too.
The RED indicates values above average, so the "Golden middle way" is where we find above average carry AND total.

The numbers i seek in this project is where we get a "optimum mix", so for 120 - 7* its a spin value of 2750, and thats means higher ball speed or higher launch, needs LESS spin than 2750

Edited May 16, 2023 by Howard_Jones

[Stuart_G]

36 minutes ago, Howard_Jones said:

Im on to a large project where im collecting numbers from Flightscope, and its NOT directly related since this tread is about spin axis or side spin vs back spin,  and my charts from this project is meant to find the "optimum" spin value for a certain ball speed and launch angle.

 

Just for clarification, do you mean the spin that will give optimum distance for a driver?

 

 

[Howard_Jones]

7 minutes ago, Stuart_G said:

 

Just for clarification, do you mean the spin that will give optimum distance for a driver?

 

 

Start parameters is ball speed and a given launch angle
- Now the job is to find what spin levels is "the best" when ball speed and launch is fixed?

Thats what im trying to figure out, and its not MAX carry or MAX total, but where we find the crossing points who gives us good numbers on both carry and total. (a good compromize)

If it was max carry, then low ball speed and low launch say MAX spin = MAX carry, and if it was max total it would say minimum spin, but we already knows that, and those ends of the scale is not very realistic ether, so im try to find the spin levels we should be within where we get a good mix of both, and here is everything from 2100 to 3000 rather good numbers, the "best" mix is at 2750

[Howard_Jones]

Here is how it looks like with the same low 120 mph ball speed, but with 17* as launch
Then MY judgement is that 2050 rpm is "the best mix" of Carry and Total.

For short, at only 120 mph ball speed, and launch from 7* to 17* (10 difference), a spin reduction of 700 is wanted (70 lower rpm for each 1* launch goes up)

[Stuart_G]

36 minutes ago, Howard_Jones said:

Start parameters is ball speed and a given launch angle
- Now the job is to find what spin levels is "the best" when ball speed and launch is fixed?

Thats what im trying to figure out, and its not MAX carry or MAX total, but where we find the crossing points who gives us good numbers on both carry and total. (a good compromize)

 

In some cases - really depends more on the course conditions the player tends to play more often.

 

But the main thing that I wanted to verify that it was driver distance you were looking at (whether carry, total, or some compromise wasn't really as important to my question).

 

 

 

Edited May 16, 2023 by Stuart_G

[RentDeezy12]

Mizuno Distance Maps.pdf

Edited May 16, 2023 by RentDeezy12
Added photo

[chollier986]

5 hours ago, Stuart_G said:

 

No.  That's faulty logic.  The spin axis alone is not an accurate representation of how straight the ball will go or how far it will go offline.   The side and back spin components effect the ball flight independently.   So the same side spin will have (basically) the same horizontal curve even if the spin axis is different.   That's why if you want to understand the effect on the ball flight - it's always better (less confusing) for most to look at the back and side spin numbers than it is the spin axis number.

 

Side spin tells us how it will curve (horizontally).   Back spin (and other aspects of the launch conditions) will tell us how far it will go or how long it will stay in the air to continue that horizontal curvature.   The only universal generalization is that - the farther the ball goes - the more it will continue to go offline.    Other than that, the complexity of the problem makes any other generalization pretty unreliable.

 

 

 

I tend to agree - at least as generalizations go.  Some may have some truth to them but only is very limited contexts.

 

 

You’ve started to deviate from the OPs original question, which has made you take my comment out of context.  I’ll agree that there are many parameters that impact how far offline a ball will travel, spin axis being a key component.  A driver with 3000 rpm backspin will be inherently harder to curve than a diver with 1200 rpm backspin.  Stated another way, a driver with 1200 rpm backspin will be inherently easier to curve than a driver with 3000 rpm backspin. 

[Stuart_G]

48 minutes ago, chollier986 said:

You’ve started to deviate from the OPs original question, which has made you take my comment out of context.  I’ll agree that there are many parameters that impact how far offline a ball will travel, spin axis being a key component.

 

I don't believe I did take it out of context.

 

48 minutes ago, chollier986 said:

 A driver with 3000 rpm backspin will be inherently harder to curve than a diver with 1200 rpm backspin.

 

That's exactly the context I was disagreeing with in your previous post.  

 

Curvature and the offline tendencies are not about the amount of backspin - it's about the amount of side spin.  It's even less true in the case of drivers due the potential for large amounts of gear effect to influence side and back spin in very independent ways.   

 

or to put it another way, the same side spin and same distance (and hang time) will also give basically the same offline distance  regardless of how different the back spin might be.

 

 

 

 

Edited May 16, 2023 by Stuart_G

[GungHoGolf]

4 hours ago, Howard_Jones said:

Im on to a large project where im collecting numbers from Flightscope, and its NOT directly related since this tread is about spin axis or side spin vs back spin,  and my charts from this project is meant to find the "optimum" spin value for a certain ball speed and launch angle.

120 mph ball speed and only 7 launch is "bad numbers", and this is really the only starting point (or lower), where we can see that spin can stretch carry, but since high spin levels reduces roll out as much as it does, even with only 120 ball speed and 7 launch, MY conclusion is that more than 3000 rpm spin is NOT beneficial for this player either.

I will not "jump to conclusion" for what it looks like when im done for all relevant ball speeds up to 200 mph, but i have a feeling that there IS a "golden number" for spin thats "good for all", and it seems to be about 2100 rpm, who actually is enough spin for 120 - 7* too.
The RED indicates values above average, so the "Golden middle way" is where we find above average carry AND total.

The numbers i seek in this project is where we get a "optimum mix", so for 120 - 7* its a spin value of 2750, and thats means higher ball speed or higher launch, needs LESS spin than 2750

Those Time and Height numbers can’t be right, right?

[glm]

 to answer your question IMO more back spin helps, more side spin hurts

 

 

[Howard_Jones]

8 minutes ago, GungHoGolf said:

Those Time and Height numbers can’t be right, right?

Its a comma missing, so 241 is actally 24.1 for height, and the same for TIME where 38 is 3.8

There is issues when importing CVS files and the origin is USA and the user like me is in Europe, since we use different signs to split numbers. That means i have to convert all numbers by deviding on 10, but did not do that for height and time

[chollier986]

34 minutes ago, Stuart_G said:

 

I don't believe I did take it out of context.

 

 

That's exactly the context I was disagreeing with in your previous post.  

 

Curvature and the offline tendencies are not about the amount of backspin - it's about the amount of side spin.  It's even less true in the case of drivers due the potential for large amounts of gear effect to influence side and back spin in very independent ways.   

 

or to put it another way, the same side spin and same distance (and hang time) will also give basically the same offline distance  regardless of how different the back spin might be.

 

 

 

 

What is your take on why a golfers lateral dispersion with a wedge is far tighter than with a 7 iron and even more so than with a driver?

[Stuart_G]

2 minutes ago, chollier986 said:

What is your take on why a golfers lateral dispersion with a wedge is far tighter than with a 7 iron and even more so than with a driver?

 

Simple.  The total distance of a wedge is a lot shorter than that of a 7 iron.  As I already said - how far offline a shot will (or can go) is more about the total distance of the shot than anything else.

 

On top of that, the shorter playing length and slower swing speeds (and the lake of any typical attempts to get the most distance from the shot) makes it much easier to manage face-to-path control for most golfers.

 

The higher spin certainly didn't keep Bubba from being able to hook his 52* gap wedge 40 yards at Augusta in 2012 during the playoff. 

[DLiver]

While the description of spin and its associated vectors is very helpful to engineering types (those familiar with vector analysis, etc), it tends to perpetuate the idea that there are different types of spin: side spin and backspin. In reality, there is only spin. The ball doesn't spin partly sideways and partly backwards, it just spins. How that ball is oriented (spin axis) determines what forces act on the ball. Mostly there is a force upward (lift) and a force to the side. I like to think of how an airplane flies: with its wings level the major force is up--lift. When the wings are tilted--which creates a vector of force to the side, and the plane turns.

 

The more a ball spins, the greater these component forces will be. Conversely, the less the ball spins, the lower these forces will be. A less spinney ball (or driver head) curves less and produces less lift.

 

I suspect some pros are finding that certain ball/head combinations make it hard for them to play a shot shape, which many prefer in order to increase the directional control of their shots off the tee. However I am just guessing about this.

[rbpwrx]

15 hours ago, nkurz said:

(I'm pretty sure I'm right that increased backspin never reduces horizontal curvature, but not 100% confident.  If Part 1 was true about the angular momentum changing things, it's possible some other effect comes in.)

I'm no expert, but it does seem to me that the more vertical backspin you have, the smaller the sidespin component (spin axis tilt) will be, as a percentage of total spin, AND (perhaps) the more backspin will tend to overpower or 'correct' sidespin (?)

I don't know if a dimpled golf ball in air behaves this way, but many spinning bodies seem to stabilize around their *primary* direction of spin. I'm thinking of tops, centrifuges, planets, washers, gyroscopes, wheels, etc.

Maybe that's why short irons go straighter, even though its face angle probably isn't any less crooked. Rocco Mediate says "Spin is control. See how that works?"

And maybe that's why low-spin drivers go haywire - because the sidespin component is proportionally much larger...?
 

[chollier986]

38 minutes ago, Stuart_G said:

 

Simple.  The total distance of a wedge is a lot shorter than that of a 7 iron.  As I already said - how far offline a shot will (or can go) is more about the total distance of the shot than anything else.

 

On top of that, the shorter playing length and slower swing speeds (and the lake of any typical attempts to get the most distance from the shot) makes it much easier to manage face-to-path control for most golfers.

 

The higher spin certainly didn't keep Bubba from being able to hook his 52* gap wedge 40 yards at Augusta in 2012 during the playoff. 

You reference bubbas shot because it was impressive.  Much less impressive to do that with a driver. 
 

 

[Stuart_G]

35 minutes ago, DLiver said:

While the description of spin and its associated vectors is very helpful to engineering types (those familiar with vector analysis, etc), it tends to perpetuate the idea that there are different types of spin: side spin and backspin. In reality, there is only spin. The ball doesn't spin partly sideways and partly backwards,

 

While true - the thought that it might spin in two separate directions (while not physically true) doesn't really hurt their understanding of how the ball flys - because it still true from a mathematical basis.

 

35 minutes ago, DLiver said:

The more a ball spins, the greater these component forces will be. Conversely, the less the ball spins, the lower these forces will be. A less spinney ball (or driver head) curves less and produces less lift.

 

That's true - but the problem is that it's only true IF the spin axis is the same for the different spin levels.    The more important point is that the amount of spin doesn't restrict the tilt in a way that reduces the resulting side spin and curvature.

 

Edited May 16, 2023 by Stuart_G

[Stuart_G]

2 minutes ago, chollier986 said:

You reference bubbas shot because it was impressive.  Much less impressive to do that with a driver. 
 

 

Impressive or not, it proves that it is possible - and therefore spin is not the limiting factor.

[chollier986]

10 minutes ago, Stuart_G said:

 

Impressive or not, it proves that it is possible - and therefore spin is not the limiting factor.

Yes, all things are possible.

 

When trying to hit it straight with the driver, spin is your friend.