Does a fastball rise?

[CoachRich]

Hi all,
My dad and I are having a discussion about fastballs rising. As I kid, he taught me the principal of getting backspin on my pitches to get them to rise, and we would watch Major Leaguers whose ball looked like it hopped at the end. A few years ago, however, I came across an article on the Internet about the physics of a pitched baseball, showing how it was impossible to get a fastball to actually rise. Here's the article, from Popular Mechanics:

http://www.popularmechanics.com/outdoors/sports/1283281.html?page=2

My dad insists that it's a bunch of BS - a physicist who's probably never played baseball in his life throwing out a bunch of scientific facts and laws of physics to sound like he's an expert. He also asks why a softball pitcher can throw a rise without gravity affecting it.

Here are my answers to him, and I'd love to get some opinions from the experts in this forum - I really respect everyone's knowledge here:

- You said you want to see a test of a ball projected parallel to the ground. I understand "seeing is believing" - I often feel the same way, so no argument there. But your test would be flawed - a pitcher never throws a baseball parallel to the ground. The path of the ball coming out of a pitcher's hand from on top a mound is always downhill. I think that's one of the reasons that the forces you're describing just can't happen. It's not just a matter of making a flat pitch go up, but making a downhill pitch change directions, and I don't think that can be done.

- Maybe you're assuming that the plane of a bat is totally level, too, and that a batter swings under a ball beause the ball is rising. In actuality, the bat plane for good hitters is a slight uppercut. So when the bat passes under the ball it's either because a harder thrown ball stays up longer, or it is faster to the hitting spot than the bat is.

- A softball pitcher (or submariner) can throw a rise or upshoot because the starting point is lower and the trajectory is up, not down. It's all about gravity, and a softball with an upward trajectory doesn't have to fight gravity as much as a baseball with a downward trajectory. Gravity of course will eventually work against a rise ball - just not before it gets to the batter.

- Whether the guy played or not doesn't change the rules of physics

[Williamsburg2599]

Hi all,
My dad and I are having a discussion about fastballs rising. As I kid, he taught me the principal of getting backspin on my pitches to get them to rise, and we would watch Major Leaguers whose ball looked like it hopped at the end. A few years ago, however, I came across an article on the Internet about the physics of a pitched baseball, showing how it was impossible to get a fastball to actually rise. Here's the article, from Popular Mechanics:

http://www.popularmechanics.com/outdoors/sports/1283281.html?page=2

My dad insists that it's a bunch of BS - a physicist who's probably never played baseball in his life throwing out a bunch of scientific facts and laws of physics to sound like he's an expert. He also asks why a softball pitcher can throw a rise without gravity affecting it.

Here are my answers to him, and I'd love to get some opinions from the experts in this forum - I really respect everyone's knowledge here:

- You said you want to see a test of a ball projected parallel to the ground. I understand "seeing is believing" - I often feel the same way, so no argument there. But your test would be flawed - a pitcher never throws a baseball parallel to the ground. The path of the ball coming out of a pitcher's hand from on top a mound is always downhill. I think that's one of the reasons that the forces you're describing just can't happen. It's not just a matter of making a flat pitch go up, but making a downhill pitch change directions, and I don't think that can be done.

- Maybe you're assuming that the plane of a bat is totally level, too, and that a batter swings under a ball beause the ball is rising. In actuality, the bat plane for good hitters is a slight uppercut. So when the bat passes under the ball it's either because a harder thrown ball stays up longer, or it is faster to the hitting spot than the bat is.

- A softball pitcher (or submariner) can throw a rise or upshoot because the starting point is lower and the trajectory is up, not down. It's all about gravity, and a softball with an upward trajectory doesn't have to fight gravity as much as a baseball with a downward trajectory. Gravity of course will eventually work against a rise ball - just not before it gets to the batter.

- Whether the guy played or not doesn't change the rules of physics

We discussed this over in the Between Innings (http://www.baseball-fever.com/showthread.php?t=48376) forum if it is possible, and basically everyone agreed that it is. While it may seem to rise, it's an illusion. Even if he's never SEEN a baseball, the physics guy is right.

[Jake Patterson]

Hi all,
My dad and I are having a discussion about fastballs rising. As I kid, he taught me the principal of getting backspin on my pitches to get them to rise, and we would watch Major Leaguers whose ball looked like it hopped at the end. A few years ago, however, I came across an article on the Internet about the physics of a pitched baseball, showing how it was impossible to get a fastball to actually rise. Here's the article, from Popular Mechanics:

http://www.popularmechanics.com/outdoors/sports/1283281.html?page=2

My dad insists that it's a bunch of BS - a physicist who's probably never played baseball in his life throwing out a bunch of scientific facts and laws of physics to sound like he's an expert. He also asks why a softball pitcher can throw a rise without gravity affecting it.

Here are my answers to him, and I'd love to get some opinions from the experts in this forum - I really respect everyone's knowledge here:

- You said you want to see a test of a ball projected parallel to the ground. I understand "seeing is believing" - I often feel the same way, so no argument there. But your test would be flawed - a pitcher never throws a baseball parallel to the ground. The path of the ball coming out of a pitcher's hand from on top a mound is always downhill. I think that's one of the reasons that the forces you're describing just can't happen. It's not just a matter of making a flat pitch go up, but making a downhill pitch change directions, and I don't think that can be done.

- Maybe you're assuming that the plane of a bat is totally level, too, and that a batter swings under a ball beause the ball is rising. In actuality, the bat plane for good hitters is a slight uppercut. So when the bat passes under the ball it's either because a harder thrown ball stays up longer, or it is faster to the hitting spot than the bat is.

- A softball pitcher (or submariner) can throw a rise or upshoot because the starting point is lower and the trajectory is up, not down. It's all about gravity, and a softball with an upward trajectory doesn't have to fight gravity as much as a baseball with a downward trajectory. Gravity of course will eventually work against a rise ball - just not before it gets to the batter.

- Whether the guy played or not doesn't change the rules of physics

My dad IS a physicist so we have had long discussions about the same.

The resitance backspin creates allows conditions to exist that maintain a "straighter" trajectory. No matter how much backspin you put on the ball however, gravity ultimately wins.

Case in point - I was a shooter in the service and learned quickly that even a spinning bullet drops over time and distance.

[Drill]

The earth is round

yes a fast ball rises


drill



I think, and probably others do here too, that its not good policy to make swing decisions with your kid based on internet viewing of one swing by people you dont even know. Thats no insult to anyone, its just common sense. Yes, there are people here who know what they are talking about but people to post poor video of swings.

My kids pro keeps me in the Loop of everything hes having my son doing with his swing. In fact he depends on my to tell him whats going on with it, both in practice when the Pro is pitching, and during game times and hitting sessions with me.

Get your boy to a pro hitting clinic and get involved with his swing. Posting one fast motion video, obviously that's not how he swings, aint going to cut it. It looks to me like hes not loading at all.

[Mark H]

If it rises above what the hitter expects, that is what's important.

As to softball and the "rise" pitch, which gives the appearance of rising a LOT more than any baseball pitch, video analysis of one of the best female riseball pitchers in the country showed a possible slight rise during the first ten feet or so but it was dropping from it's initial trajectory through the zone. However; if you caught or hit against this kid you would swear an oath before God and man that it curved/hopped upward just before the plate. Bottom line, your eyes CAN lie to you. Doesn't mean there's not a pitcher out there who could do better. Just means your eyes CAN lie to you.

[CoachRich]

Glad you mentioned the fastpitch, because I have been reading that it, too, is an illusion. I stopped playing baseball after high school, and never played at the varsity level anyway, so I've never faced a baseball pitcher whose ball seemed to hop. But I did play men's fastpitch for several years, and caught my dad and other pitchers. I can tell you that it sure didn't seem like an illusion. I assumed that the reason a softball can rise is that the trajectory is different, but from what I'm reading here and elsewhere on the Internet, a softball may be affected by gravity as much as a baseball is.

[scorekeeper]

The path of the ball coming out of a pitcher's hand from on top a mound is always downhill. I think that's one of the reasons that the forces you're describing just can't happen. It's not just a matter of making a flat pitch go up, but making a downhill pitch change directions, and I don't think that can be done.

CoachRich,

Although what you’re saying is basically true, I’m afraid you’re not quite right on that one. Very often a P has to throw the ball with a slight upward trajectory.

[virg]

... and furthermore a great catcher's snap peg to Second doesn't hop!

[CoachRich]

CoachRich,

Although what you’re saying is basically true, I’m afraid you’re not quite right on that one. Very often a P has to throw the ball with a slight upward trajectory.

Can you add to this, Scorekeeper? I'm not really doubting you, I'm just trying to imagine a pitcher throwing with an upward trajectory. I'm picturing a traditional, over-the-top fastball, from a mound 10" above the playing surface. In that situation, could a pitcher with ordinary stature actually have an upward trajectory? How about someone shorter, Like Billy Wagner? I don't have any visuals to aid in seeing it myself. I can look around when I get to my home pc though (most blocked here at work) and maybe I can see what you mean.

[TG Coach]

CoachRich,

Although what you’re saying is basically true, I’m afraid you’re not quite right on that one. Very often a P has to throw the ball with a slight upward trajectory.

If a strike zone is approximately two to four feet off the ground, who's pitching .... Tom Thumb?

A fastball doesn't rise. A fast fastball's trajectory will descend at a slower rate than a normal speed fastball, providing the illusion of a rise. The pitch isn't where the hitter's brain is telling him it should be. Simple answer .... gravity.

[brett]

Hi all,
My dad and I are having a discussion about fastballs rising. As I kid, he taught me the principal of getting backspin on my pitches to get them to rise, and we would watch Major Leaguers whose ball looked like it hopped at the end. A few years ago, however, I came across an article on the Internet about the physics of a pitched baseball, showing how it was impossible to get a fastball to actually rise. Here's the article, from Popular Mechanics:

http://www.popularmechanics.com/outdoors/sports/1283281.html?page=2

[/I]

The Magnus effect does keep the ball from falling as fast and based on the estimate in the article, the ball would have to have a backspin of 3600 RPM to rise, and that the maximum RPMs ever measured are about 1800, but if the ball were scuffed the magnus effect could in theory be great enough to cause it to rise. Also in a very humid environment, the effect would be greater, though I don't think it would be enough.

[calgofo]

The following equations demonstrate the manipulation of characteristics needed to determine the lift force generated by inducing a mechanical rotation on a ball.


F=1/2pV(squared)ACl


F = lift force
ρ = density of the fluid
V = velocity of the ball
A = crossectional area of ball
Cl = lift coefficient
The lift coefficient is very dependent on the spin ratio ( (angular velocity*diameter)/(2* linear velocity) ) of the ball. Lift coefficient may be determined from graphs of experimental data using Reynolds number and spin ratio. Typical lift coefficients of a smooth ball range from 0.2 to 0.6 for spin ratios ranging from 0.5 to 4.5.

[Drill]

The following equations demonstrate the manipulation of characteristics needed to determine the lift force generated by inducing a mechanical rotation on a ball.


F=1/2pV(squared)ACl


F = lift force
ρ = density of the fluid
V = velocity of the ball
A = crossectional area of ball
Cl = lift coefficient
The lift coefficient is very dependent on the spin ratio ( (angular velocity*diameter)/(2* linear velocity) ) of the ball. Lift coefficient may be determined from graphs of experimental data using Reynolds number and spin ratio. Typical lift coefficients of a smooth ball range from 0.2 to 0.6 for spin ratios ranging from 0.5 to 4.5.



that answers the question for me


thanks,

drill

[wogdoggy]

The following equations demonstrate the manipulation of characteristics needed to determine the lift force generated by inducing a mechanical rotation on a ball.


F=1/2pV(squared)ACl


F = lift force
ρ = density of the fluid
V = velocity of the ball
A = crossectional area of ball
Cl = lift coefficient
The lift coefficient is very dependent on the spin ratio ( (angular velocity*diameter)/(2* linear velocity) ) of the ball. Lift coefficient may be determined from graphs of experimental data using Reynolds number and spin ratio. Typical lift coefficients of a smooth ball range from 0.2 to 0.6 for spin ratios ranging from 0.5 to 4.5.



clear enough,,thanks