EVERYTHING YOU NEED TO KNOW ABOUT SPIN EFFICIENCY - What is Gyrospin?

[@UrMom-gw5mo]

I can’t find it but I remember reading an article claiming that gyrospin causes lateral movement. It said that as the ball changes direction downwards because of gravity its axis remains the same. This causes the gryospin to then act as transverse spin relative to the balls increasingly downward path causing late gloveside break. What are your thoughts on this?

[@SimpleSabermetrics]

Hey Cole, thanks for the great comment! I haven’t seen much about that idea either, but it isn’t a hard one to believe. In my opinion, I’m not sure just how much gloveside break would actually occur from a small change like this one. But it’s definitely something to look into. I’ll do some research and let you know if I find anything!

[@MikeRessler]

There are a number of models that do predict this. Those models put the total break from gyro spin around 3", depending on spin rate. The 9 parameter model that TrackMan uses does not account for this. It assumes a constant force on the ball, which is definitely not the case - especially for sliders! The really interesting thing about break from gyro spin is that it comes primarily late in the pitch, after the batter has already decided to swing or not!

[@midnight5267]

Had to look this up after seeing Sandy Alcantara’s gyro sliders that have arm side run instead of breaking glove side lol.

[@SimpleSabermetrics]

Hopefully this helped clear some of that up! Gyro pitches can lead to some interesting movement profiles for sure…

[@chriskahler4944]

Great video. Thanks! My question is about the 90% degree gyrospin pitched ball (0% spin efficiency) that you plotted on the X,Y axis at 0,0. I am assuming that is 0 inches vertical break and 0 inches Horizontal break; What is the assumption for a 90% gyrospin pitch being plotted at 0,0, is it the point that a ball will hit from the point the ball is released to the point it hits the plate based upon gravity being the only force to impact the trajectory? I am trying to wrap my head around the concept of pitches having 8 inches of vertical "break" with "break" being the distance the ball stayed above the 0,0 90% gyrospin. Thanks in Advance.

[@SimpleSabermetrics]

Hey Chris - thanks for another awesome comment. I’m not sure I 100% understand your question, but I’ll do my best to clarify what I believe you’re asking. A 90 degree gyrospin pitch is spinning like a football (meaning that there is no spin aiding in the movement of the pitch in the X,Y plane) - that is what gives the pitch a 0.0 mark on our plot. The plot represents the amount of movement produced because of transverse spin and furthermore effects the amount of magnus force being produced to alter the path of the pitch from the point in which it would fall with 0 spin with gravity. I’ve got a video on that concept here: m.kzbin.info/www/bejne/bIC0h2yghMaahck Basically, the H/V Break Chart takes gravity out of the equation, and a 0,0 pitch is simply letting a pitch fall with the force of gravity. Everything else, is based on the amount of spin the pitcher is putting on the ball, along with the direction of that spin. Hopefully this helps!

[@mikem9908]

Hey, I know I'm nearly 2 years late to this party (since you posted the video), but I was hoping you could answer a question I'm stewing over today... which is what landed me on your video. In your video, you only describe degrees of gyro... what about tilt? Meaning, the right side isn't closer or further away... but higher or lower? I was led to believe in a discussion with Alan Nathan a few years back that the effects of tilt and gyro are cumulative to the measured efficiency of a an intended axis... like pure forward spin, backspin, side-spin, etc. For example, if your were attempting true forward spin, but the right side of the ball was lower (4:30 on a clock facing you), the spin efficiency (for forward spin) would be 50% (50 forward-spin, 50 side-spin). Same thing if the ball was at 45-degrees of gyro... spin efficiency would be 50% (50 forward-spin, 50 gyro). So... WHAT IF... the ball had a gyro of 45-degrees... AND a tilt of 45-degrees? Surely, the efficiency of spin couldn't be 0%? What would the spin efficiency of that down and out (RHP) pitch be - relative to the intended FORWARD spin? This is driving me nuts, any help would be appreciated... as I'm sure I'm just overlooking something simple, mathematically. ~Thanks

[@johnnywholestaff4909]

Another banger. Wednesdays are a good day! A FB with a high spin rate might not be as effective if the spin efficiency isn’t high enough. So would using a Bauer Unit or a Bauer Unit + be more helpful at least with the FB?

[@SimpleSabermetrics]

Thanks for the love, Johnny! 😉 Bauer units are definitely a helpful tool when analyzing a players arsenal. It gives you a new perspective on what is above or below average RPM compared to a pitcher’s velocity. In terms of Gyrospin, I’m not quite sure how that would factor in. Maybe I’ll do a whole video in the future about how I value the Bauer Unit metric - keep the ideas coming!

[@oldmanoutdoors4700]

Is gyrospin the same in fastpitch?

[@MikeRessler]

The same concepts apply for fastpitch.

[@cooperwillis3696]

i am 17 trying to get recruited and my 2seam has about 2000-2300rpm with around 95 to 100 spin efficiency

[@sunnylo4656]

How does a slider with 0% spin efficiency break?

[@SimpleSabermetrics]

Technically it just drops with gravity, but the separation in both the horizontal and vertical direction make it appear to have more drop/sweep than a pitchers fastball does. Thanks for the comment!

[@SimpleSabermetrics]

Also here’s a video I did comparing two pitchers with sweeping vs. gyro (or 0%) sliders in the MLB! kzbin.info/www/bejne/aKO7hmmfhc-MedU