The following article is written by J.J. Cooper of Baseball America and featured in their December 2023 issue.
The powerful Rapsodo PRO 3.0 details all key pitch characteristics.
A half century ago, some pitchers threw harder than others. Trying to quantify it beyond that was nearly impossible.
A good scout could tell you which pitcher had a better fastball when comparing two pitchers they'd seen, but trying to explain who threw harder between two pitchers on the opposite coasts of the United States was nearly impossible.
Then the radar gun was invented, and all of a sudden the difference between a 92 and 94 mph fastball could be quantified.
But some 92 mph fastballs are more effective than others. Scouts knew this, but explaining why in a quantifiable way was impossible. The tools to measure it didn't exist.
A decade ago, the ability to measure spin rates with Doppler radar units started to close that hole. Teams found that higher spin rates usually led to more effective pitches at the same velocity.
Units like the Rapsodo 1.0 allowed pitchers and coaches to better measure their spin rates, which helped quantify something that had before been only subjectively measured.
In many ways, spin rate was an indirect measurement. Two pitches with the same velocity and the same spin rate could actually be quite different.
Eventually, the addition of visual tracking allowed a pitch's spin to be measured rather than extrapolated. Units like Rapsodo 2.0 allowed pitchers to see their effective spin rate, which imparted actual movement on a pitch, rather than just measuring the total spin rate.
But even after the addition of optical tracking to go with radar measurements, some pitches moved in ways that seemed hard to explain. Two pitches thrown to the same spot, with the same velocity, with the same effective spin could still move significantly differently.
As studies at Utah State helped determine, that was because of aerodynamics of seam-shifted wake (SSW). Because of the way the air flows over the seams of a baseball, it can create areas of low-pressure that affect ball movement.
Often, this would lead to random movement of one pitch compared to another, but a savvy pitcher could figure out how to take advantage of this to make their pitches move differently than hitters would expect.
"In our lab, we didn't invent SSW. There have always been seam-shifted wake pitches," said John Garrett, an analytics engineer at Rapsodo. "There have always been pitchers who get the ball to move the way they want. We just didn't have a complete understanding. We now have a much better understanding now of what is going on in the physical sense."
Before coming to Rapsodo, Garrett was one of the researchers at Utah State working on SSW under the direction of Dr. Barton Smith.
Knowing that seam-shifted wake exists was a breakthrough, but figuring out how to take advantage of SSW was actually much more difficult. If you can't measure SSW, it's hard to know if you're managing to take advantage of it with each pitch. Pitchers could grind out sessions trying to solve the mysteries of SSW, but often it would be hard to fully understand why some pitches moved as desired while others did not.
Making it even more difficult is that there are so many different factors acting on the baseball that what creates SSW for one pitcher is not assured to do the same for another.
"This is quantitative feedback rather than qualitative feedback. This is the point the ball is rotating around and this is how the ball moved," Garrett said. "With the SSW effect, there are so many factors. There's velocity, spin rate, spin direction, the amount of gyro spin.
"You're not going to have an ideal seam-orientation that works for every single pitchers' cutter. Every pitcher will have an optimal seam orientation. It takes experimentation to create these pitches. But now we're giving qualitative information."
And that's where Rapsodo PRO 3.0 has opened a new avenue.
Rapsodo PRO 3.0 can measure seam-shifted wake by comparing how the ball actually moved with how it was expected to move-and then extrapolating how SSW led to the differences.
Because of this, and Rapsodo PRO 3.0's ability to show how a pitcher has oriented the seams, it can help a pitcher more quickly and effectively dial in on how to use SSW to their advantage. And once a pitcher can replicate SSW consistently, they can stay a step ahead of hitters.
No hitter actually follows the ball all the way to the plate. To connect with a pitch, a hitter has to extrapolate the flight of the ball from well before it crosses the plate. If the pitch moves in an unexpected way, it can confound the hitter.
"You can create a force that moves the ball in unexpected directions," Garrett said. "The baseball bat is only so wide, so a matter of a few inches can make a big difference."
Because of this, and Rapsodo PRO 3.0's ability to show how a pitcher has oriented the seams, it can help a pitcher more quickly and effectively dial in on how to use SSW to their advantage. And once a pitcher can replicate SSW consistently, they can stay a step ahead of hitters.
No hitter actually follows the ball all the way to the plate. To connect with a pitch, a hitter has to extrapolate the flight of the ball from well before it crosses the plate. If the pitch moves in an unexpected way, it can confound the hitter.
"You can create a force that moves the ball in unexpected directions," Garrett said. "The baseball bat is only so wide, so a matter of a few inches can make a big difference.
Visit our website to learn more about PRO 3.0 and Seam Orientation.
