NASA and riseballs

[nohesitation]

I asked a really smart guy at NASA the following question.

Can a rise ball spin pitch actually rise thru the hitting zone?
Pitching speed is around 73 mph and 1700 rpm.

I doubt it. you'd have to generate more than 7 oz of lift. We can get a "back of the envelope" answer using the equations on this slide:
http://www.grc.nasa.gov/WWW/K-12/airplane/beach.html

for the softball - b = 3.75/2/12 = .156 feet
s = 1700 rpm = 28.3 rev/sec
rho = .00237 slug/ft^3
V = 75 mph = 110 feet/sec

L ideal = 4*(4 * pi^2 * .156^3 * 28.3 * .00237 * 110) / 3 = 1.47 lbs

BUT ... you don't get the ideal lift you only get a portion as defined by the lift coefficient which is described here:
http://www.grc.nasa.gov/WWW/K-12/airplane/balllift.html


If we have the same lift coefficient for a baseball and a softball cl = .15

final lift = .15 * 1.47 lbs = .22 lbs = 3.54 oz ,,,,,,,,, not even half of what you need for a truly rising fast ball.

[DDsNbr1Fan]

Ok..I guess that is one way to look at it. All I know is there are an awful lot of pitchers throwing a softball that rises and even jumps up in and out of the hitting zone...and not just a high fastball. And an awful lot of batters missing the ball. Something must be happening.

[Hitmechanic]

It is my understanding that to throw a "rise ball" (i.e. "ski slope rise", not a angular low-to-high fast ball), the toss would have to be 75 MPH with a 88 RPM backspin. I also understand only three people in the world have been documented as accomplishing this toss. Two males and one female. The "King" did it and I forgot who the other two were.

Anyway, I do not a 1700 RPM softball spin is humanly possible.

Also, I think "Right View Pro" (?) or one of them jiggers has research on this subject.

In some words "The rise ball is just an optical illusion".

JMHO

[ssarge]

Ok..I guess that is one way to look at it. All I know is there are an awful lot of pitchers throwing a softball that rises and even jumps up in and out of the hitting zone...and not just a high fastball. And an awful lot of batters missing the ball. Something must be happening.

What is happening is that you are not seeing what is actually happening.

I understand your perspective. I KNOW what it looks like the pitch is doing when it is coming at you (hitter or catcher). But video taken in profile of THE SAME PITCH shows something entirely different. The pitch path can be clearly traced on video, and it NEVER hops or climbs. A REALLY skillful pitcher MIGHT be able to OCCASIONALLY throw a strike (very top of the zone) that is still SLANTING upwards (a way different deal than climbing or hopping). But it would be at an EXTREMELY small incremental rate. If the pitch was released with a 5 degree upard trajectory about the norm) it MIGHT still be climbing at the very diminished rate of 1 degree. Maybe. Occasionally. Most of the better riseball pitchers throw a ball that is flat or declining slightly as it goes through the hitting zone. Unless it is above the strike zone, and then as stated, it might be still slanting up slightly. But it will never actually rise above the trajectory estabished at release, and will never hop.

The rofile angle video is just inarguable. And if you have one that shows a hop or climb, than by all means, post it. Or eMail it to me, and I'll post it. It will be the first such video ever posted on the internet.

Typically, in this kind of thread, the response is somehting along the lines of "well, you just haven't seen a REAL riseball."

I assure you that I have. I know EXACTLY what it looks like when it is coming at yu. I have also taken profile angle video of may pitchers throwing devestating riseballs - Fernandez, Osterman, Finch, Hallowell, to name a few. Plus the Sarah Pauly project. The video shows what the video shows.

As for WHY it looks different when it comes at you, that is clearly at least partly an illusion (can't argue with the camera). I posited my theory as to what causes this on the "Baseball vs. Softball Swing" thread on this site earlier this week (towards the end of the thread). Just a theory, but as logical as anything, I suspect. Might be worth reviewing.

Best regards,

Scott

[ssarge]

It is my understanding that to throw a "rise ball" (i.e. "ski slope rise", not a angular low-to-high fast ball), the toss would have to be 75 MPH with a 88 RPM backspin. I also understand only three people in the world have been documented as accomplishing this toss. Two males and one female. The "King" did it and I forgot who the other two were.

You are probably remembering the right number, but the wrong acronym. 88 RPS (revolutions per SECOND, not per minute). Or roughly 5500 RPM. Which I understand is about what it is required to overcome the 7oz lift requirement that nohesitation laid out in his post above.

(88 RPM would be less than 1 revolution in the 0.45 second flight of a typical FP riseball).

The 1700rpm is about the outer envelope for a female ptcher. 1200-1500 is more typical for good pitchers. Probably could quibble on this a littl, but whatever - it isn't going to get anywhere close to 5500.

Best regards,

Scott

[Hitmechanic]

[You are probably remembering the right number, but the wrong acronym. 88 RPS (revolutions per SECOND, not per minute). Or roughly 5500 RPM. Which I understand is about what it is required to overcome the 7oz lift requirement that nohesitation laid out in his post above.]

Thanks for the adjustment Scott. I was thinking in RPS, just typed RPM. glad to see you here adding respect value.

BTW: Everyone "WHAT SCOTT SAID"!

[nohesitation]

Hitmechanic... Anyway.. I do not think a 1700 RPM softball spin is humanly possible.

I read a good fastball pitcher develops 1800 rpm at 100 mph and the ball rotates 16 times to the plate. I didn’t have any data on a softball. I’m with you; I see the ball jump also. The pitch may jump because the uneven laces create erratic lifts? But the pitch needs more lift force to rise.

[ssarge]

not even half of what you need for a truly rising fast ball.

Intuitively, this sounds right t me, because a good riseball seems to overcome about 1/2 of the effect of gravity - in other words, it drops about 1/2 the distance of a spin-neutral pitch thrown at the same speed.

And my intuition doesn't mean squat compared to the physics. But it is gratifying to me that my intuition is consistent with the physics.

Regards,

Scott

[ssarge]

The pitch may jump because the uneven laces create erratic lifts? But the pitch needs more lift force to rise.

If it did, there would be way to hide it from profile angle video. Part of the illusion, and part of the reason why it is so devestating a pitch, and so hard for a hitter to make contact with a good one.

Of course, riseballs are almost never thrown for a strike, so perhaps the best approach to hitting it is to not try (and instead wait for something easier to handle). Easier said than done, I know.

Regards,

Scott

[Sam]

It is my understanding that to throw a "rise ball" (i.e. "ski slope rise", not a angular low-to-high fast ball), the toss would have to be 75 MPH with a 88 RPM backspin. I also understand only three people in the world have been documented as accomplishing this toss. Two males and one female. The "King" did it and I forgot who the other two were.

You are probably remembering the right number, but the wrong acronym. 88 RPS (revolutions per SECOND, not per minute). Or roughly 5500 RPM. Which I understand is about what it is required to overcome the 7oz lift requirement that nohesitation laid out in his post above.

(88 RPM would be less than 1 revolution in the 0.45 second flight of a typical FP riseball).

The 1700rpm is about the outer envelope for a female ptcher. 1200-1500 is more typical for good pitchers. Probably could quibble on this a littl, but whatever - it isn't going to get anywhere close to 5500.

Best regards,

Scott

I'm pretty sure you can get up to 5492RPMs if your DD uses one of those fancy schmancy balls on a stick.....