Danger zone speed

[ArmWhip]

The Magnus Force is proportional to the cross-product of the angular velocity vector and the translational velocity vector. Neither of these things are constant during the trajectory of the ball hence this force (a part of the force acting on the ball which makes it move) will not be constant. I would probably expect the magnitude of this Force to actually decrease during flight hence if this force produces a component which opposes gravity, which is pretty much constant, then "late movement" (in the direction of gravity) would be expected in this case. This is probably what you are seeing with a splitter, which has less backspin then a regular fastball. During it's whole trajectory it is going to drop more than a 4 seam fastball but there may be a bigger change (decrease) in the Magnus force during the end of the trajectory which causes it to drop more...not sure.

As a general statement, fluid dynamics is an inherently unsteady phenomena and the fluid dynamics of a baseball trajectory is no different. Hence the forces produced to move a ball during flight will not be constant. Knuckleball movement in baseball is the most obvious result of this unsteadiness..

In the tradition of Albert Einstein let's try a little thought experiment. Let's go to the Grand Canyon and throw a perfect bullet spin pitch off of a cliff. The ball starts out with a perfectly horizontal trajectory and since it's bullet spin there is no Magnus force present. As the ball loses momentum and it's trajectory starts to change the gyroscopic effect keeps the spin axis horizontal. The ball continues to lose forward momentum and you might think that it will simply drop in an ever steeper trajectory, in a straight line down until it hits the ground. But this is not the case, as the ball begins to drop air flow over the ball increases from the bottom to the top and this generates Magnus force. From the perspective of the thrower if the ball has clockwise bullet spin the ball will 'curve' to the left as it drops. The steeper the drop the more it 'curves'. So a bullet spin pitch which started out dead straight ends up curving, in baseball it's the slider.

 

[_MIA_]

In the tradition of Albert Einstein let's try a little thought experiment. Let's go to the Grand Canyon and throw a perfect bullet spin pitch off of a cliff. The ball starts out with a perfectly horizontal trajectory and since it's bullet spin there is no Magnus force present. As the ball loses momentum and it's trajectory starts to change the gyroscopic effect keeps the spin axis horizontal. The ball continues to lose forward momentum and you might think that it will simply drop in an ever steeper trajectory, in a straight line down until it hits the ground. But this is not the case, as the ball begins to drop air flow over the ball increases from the bottom to the top and this generates Magnus force. From the perspective of the thrower if the ball has clockwise bullet spin the ball will 'curve' to the left as it drops. The steeper the drop the more it 'curves'. So a bullet spin pitch which started out dead straight ends up curving, in baseball it's the slider.

Yes, like I said assuming that anything about the force on a ball is constant during it’s trajectory is silly .

 

[sluggers]

So a bullet spin pitch which started out dead straight ends up curving, in baseball it's the slider.

It is more complicated than that. With a slider, the axis of rotation of the ball is not collinear with the direction of movement. This means that the seams are distributed asymmetrically on the spinning ball, and thus there is more drag on one side of the ball than the other. As pointed out by @pattar , this is called "seam shifted wake" by the physicists.

The best example of seam-shifted wake in softball is a Rachel Garcia riseball she threw in the CWS.





The pitch is very difficult to perfect. Even Garcia made mistakes with it...and a mistake means it is a high fastball.



For the nerdily inclined, here is some more information: https://rocklandpeakperformance.com/what-is-a-seam-shifted-wake-pitch/

In the far distant future, when humandkind travels to the stars, softball people will still be arguing over this.

 

[_MIA_]

As pointed out by @pattar , this is called "seam shifted wake" by the physicists.

I didn’t point that out in this thread

 

[Godfather]

It is more complicated than that. With a slider, the axis of rotation of the ball is not collinear with the direction of movement. This means that the seams are distributed asymmetrically on the spinning ball, and thus there is more drag on one side of the ball than the other. As pointed out by @pattar , this is called "seam shifted wake" by the physicists.

The best example of seam-shifted wake in softball is a Rachel Garcia riseball she threw in the CWS.





The pitch is very difficult to perfect. Even Garcia made mistakes with it...and a mistake means it is a high fastball.



For the nerdily inclined, here is some more information: https://rocklandpeakperformance.com/what-is-a-seam-shifted-wake-pitch/

In the far distant future, when humandkind travels to the stars, softball people will still be arguing over this.

Not to jump off topic but your phrase "difficult to perfect" is sticking with me. If you had a choice between this pitch and a true backspin riseball, would you have a preference? I've been around the forums for a long time and the consensus seems to be pure backspin is the way to go if the pitcher can do it. But I am also hearing some college coaches preferring this "Garcia" style pitch.

 

[_MIA_]

Not to jump off topic

lol..it has been off topic for 4 pages now

 

[jfitch12]

So a bullet spin pitch which started out dead straight ends up curving, in baseball it's the slider.

I always thought of the curve in softball as similar (or in the same family) as a baseball slider, since both are predominantly bullet spin with glove-side run. This is a really good explanation why they move despite being predominantly bullet spin (sometimes with a little upward tilt of the axis).

I am not sure about the role of seam-shifted wake for the slider. I’m not an expert but had always understood that seam-shifted wake applied more to two-seam fastballs and changeups (in baseball)—at least more so than bullet-spin pitches.


Sent from my iPhone using Tapatalk

 

[ArmWhip]

A seam shifted wake pitch requires a seam to be consistently present where the air separates from one side/spot of the ball, this is what shifts the wake. Pure spins like back/top, bullet or curve don't allow this to happen, the spin has to be 'tilted' at an angle close to 45 degrees. Both spin direction and seam orientation have to be correct for the ball to break.

 

[Mike-Coach Q]

I was never a believer in 'late break' but then I read something that changed my mind. As a pitch nears the plate it will be losing velocity and this will change the ball's trajectory, it will drop more. A curve with perfectly horizontal spin will lose Magnus force as it slows down, it's trajectory angles down more, and it will break less. A curve thrown with the spin axis tilted forward a little will get an increase in Magnus force as it slows down and it's trajectory angles down, it break more at the end.

One thing that I find useful is to think about spin pitches in terms of RPF rather than RPM"S. That's revolutions per foot vs revolutions per minute. A 50mph pitch thrown with the same RPM's as a 60mph pitch will have more RPF's and break more.

I explain it to my students that are learning spins; spin and speed are always fighting, spin wins the ball breaks, speed wins the balls goes straight . This explains why they can spin it correctly but not get the desired results.

 

[Tango]

Thought this was interesting two 2024 pitchers. Neither are my daughter. College coach goes on a long spill about how he recruits pitchers that get outs and not speed. Told them about playing a D1 team and giving up 30 runs and the only kid that could get anyone out was a spinner that threw 52-55.

One kid throws 52-56 (normally 54) and shut the college team down for three innings (no runs). Her team made several errors and she got out of jams. Nothing hit hard. The college PC saw her throw at the camp and the first drop she threw she said that's the pitch we couldn't hit. Then threw her change and she just shook her head.

Other kid 63/64 and got hammered. Gave up 7 in the first inning.

They offered the kid that threw 63/64 and told the spinner that they will keep an eye on her.