Movement on a fastball

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May 15, 2016
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Forgive me for a newbie question. In another thread there was a discussion about movement on a fastball. What kind of movement can happen on a fastball pitch?
 
Feb 26, 2017
22
0
My DD fastball breaks down and away from a rhb. Winter project is to learn to make it break the other way too.
 
May 15, 2016
926
18
My 13y/o DD, who started pitching this past July, has some pretty good speed on her pitch. She mentioned to me she recently noticed the ball seem to rise and then drop as it is approaching the plate. I had not prompted her to say anything about movement. I thought I was seeing the same thing, but then again, I am a newbie and know nothing about this. Is that possible?
 
May 30, 2013
1,442
83
Binghamton, NY
Most FB's aren't strait-away bullet spin.
I think if you are chucking one 60+ with reasonable spin rate (15+),
that ball is going to move, at least a little.
 
Feb 3, 2010
5,752
113
Pac NW
She mentioned to me she recently noticed the ball seem to rise and then drop as it is approaching the plate. I thought I was seeing the same thing, but then again, I am a newbie and know nothing about this. Is that possible?

Here's a post by pobguy that discusses this:

CORRECTION: I had earlier said 75 rps was about the spin needed for the ball to rise above its initial plane, assuming 70 mph release speed. I messed up (yes, even physicists do that, more often than you think; but, we are very good at finding our mistakes). It is more like 60 rps, still about twice what RevFire gives for elite players. The numbers for the spin in the slides I posted earlier are not my own numbers. The PITCHf/x system does not measure the spin. It measures the movement and used that to infer the spin, with the aid of a model. I don't recall offhand whether the model that is used is the best one available, so the absolute numbers for spin should be taken with a grain of salt. The numbers for movement are much more reliable.


I don't know what that means.

RPM (Oops! Should be RPS! Thanks corlay!)
 
Last edited:
May 15, 2016
926
18
RPM (Oops! Should be RPS! Thanks corlay!)

Ok, the spin rate means the rps, but what does the 15+ mean?

Does "strait-away bullet spin" mean the ball is rotating on a axis that is pointing the the catcher?

You included the pobguy post, I have to doubt that my DD is throwing anything like 60 rps. She is throwing faster than any other pitcher on her 14u team (she just turned 13), but it is a B team. I also doubt she is throwing anything like the speed of the top 13year olds around.
 

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