Inside Pitch Magazine, January/February 2020

The Hot Corner: Utilizing the Rapsodo 2.0 Pitching Unit

How to get started with your new toy

By Bo Martino, Los Angeles Angels Minor League Pitching Coach

Baseball has taken a turn towards the tech era. What was once only available to pro organizations and colleges with big budgets has now started to trickle down to smaller colleges, high schools and training facilities. One of the main pieces of technology that has taken off is the Rapsodo 2.0 pitching unit. This unit is a camera and radar-based system that uses images to read velocity, spin rate, movement, etc. With so many people starting to get these units and Bahram Shirazi of Rockland Peak Performance covering what pitch design in the July/August 2019 issue of magazine, I wanted to cover how we implemented and applied the data at Stephen F. Austin State University. 

1. Fastball Spin Rate and Bauer Units 

The first step of assessing our pitchers is to look at their spin rate and velocity to convert those into a Bauer Unit (BU). A BU is used to normalize spin per the velocity of a pitch. Think of it like an ACT score, there are multiple sections that go into an ACT score but they are converted to a single number so people can compare scores. The formula to convert to BUs is simply the spin rate divided by the velocity of the pitch (BU = spin rate/velocity).  

Rapsodo ChartFigure 1

Now that we know how to compute a BU, we must figure out the spin profile of our fastball. These can be categorized in BU profiles: 1. Low spin 2. Average spin or 3. High spin rate for that velocity. The MLB average BU for a fastball is 23.5 – 25.5. A low BU might mean that a pitcher could have success working middle to down in the zone, while a high BU might mean that pitcher could have success middle to up in the zone. If the BU is average, then the focus should be on the movement specifically, potentially moving from a 4-seamer to a 2-seamer and/or a change in specific grip, etc. The Bauer Unit chart (Figure 1) covers the MLB average BUs for the fastball (FB) and breaking ball (BB) while the total spin chart (Figure 2) and velocity chart (Figure 3) shows the average spin rate and velocity on all pitches for MLB pitchers per Rapsodo MLB Data Guide.


Rapsodo ChartFigure 2

Rapsodo ChartFigure 3

2. Fastball Spin Direction (axis) and Spin Efficiency 

Next you want to look at the spin direction (axis) and the spin efficiency of the fastball. The spin direction (axis) of a pitch is based on the face of a clock from the pitcher’s point of view at ball release, 12:00 is all backspin (a true 4-seam fastball-type spin), 6:00 is all top spin (a true curveball-type spin), 3:00 is side spin for a RHP (slider-like spin) and 9:00 is side spin for a LHP (slider-type spin):

Rapsodo ChartFigure 4

If we have a high BU and want to throw the ball up in the zone successfully, we want to create more backspin to potentially help our fastball to have a higher positive vertical movement. This creates the “ride” effect, which in turn helps the fastball sink less and/or stay up (ride) longer through the strike zone or above the strike zone. We would be looking for the spin direction (axis) for a RHP to be more towards 12:00 to 12:30. The spin direction (axis) for a lower BU pitcher could be tilted more to the 1:00 position, or past, to allow the fastball to move less vertically and more horizontally and create more sink and less true “ride.” Changing the spin direction (axis) will cause the baseball to move differently for whatever desired outcome.

Spin efficiency is how much of the spin that is being produced by the pitcher is helping that pitch move. It is measured from 0-100% and is directly related to a pitch’s gyro degree which is 0°-90°. A reading of 100% spin efficiency, or 0° gyro degree, means that all the spin that is produced is helping that pitch move along the spin direction (axis). 90° gyro degree means just the opposite and that none of the spin is helping the ball move and looks more like bullet spin. All pitch types that are thrown will have a different spin efficiency range that they fall into. We want the fastball to be somewhere between 85-100% efficiency and towards the top end of this range if we are a high BU pitcher. If our pitcher is lower than this range, then he is not getting the most out of, or maximizing what his fastball characteristics offer with vertical movement, horizontal movement and/or velocity. The spin efficiency chart (Figure 5) shows the ranges for most pitches thrown by MLB pitchers and the gyro illustration (Figure 6 & 7) shows the different gyro degrees on pitches per Rapsodo Data Guide:


Rapsodo ChartFigure 5

Rapsodo ChartFigure 6

Rapsodo ChartFigure 7

3. Off Speed Pitches Paired with Fastball 

Now that we know what our fastball is doing, we need to see how the rest of our pitches match up with our fastball. If we have a high BU fastball pitcher, then a more 12-6 type curveball will match up better due to potential tunneling effect/separations of break that play off each other well to maximize that pitcher’s angles. With a high BU fastball pitcher wanting to work up in the zone, a curve ball pairs well because it has to start up in the zone before breaking down. A low BU fastball pitcher potentially wants to be able to work down in the zone more, maximizing their movement profile/angles and utilizing more horizontal movement to their breaking balls like that of a slider or slurve. Curveballs do not pair as well with a low BU fastball due to an increase in horizontal movement that is likely on the fastball. This movement doesn’t share the ideal matching movement profile with the curveball that likely has minimal horizontal movement and more negative vertical movement compared to the slider or slurve that can show higher horizontal movement to maximize the angles of the low BU fastball. With change ups, we want to make sure there is a separation between it and the fastball by velocity, horizontal and vertical movement.  

The dots on the vertical and horizontal break chart (Figure 8) need to be farther away from each other. Here we can see how the fastball (FB) and the curveball (CU) are working across from each other as well as the cutter (FC) and change up (CH) are working horizontally across from each other:


Rapsodo ChartFigure 8

All the dots have separation from each other as well. This separation can be created by more things than just velocity. We can start to change the spin direction and spin efficiency of a pitch to get a different result maximizing the movement profiles (horizontal movement and vertical movement). The closer the dots are, the less difference in movement between the pitches. The dots on the vertical and horizontal break chart (Figure 8) need to be farther away from each other. Sometimes pitchers have 4 seam fastballs/2 seam fastballs or curveballs/sliders that move the same way. If this happens, we can either create separation between the two pitches or we can get rid of the one that is not as effective. For example, if we have a curveball and slider that move identically by their movement profiles, but the slider has a high BU and pairs well with our fastball, then we would likely keep the slider. With that said, don’t give up a plus pitch for a pitcher just because it doesn’t pair well.   

4. Putting your Plan into Action 

These steps should give you an idea of where to start to find out who your pitchers are based off your Rapsodo data/information and is to be used as a basic guide. Creatively, you now have to find ways to use the info you gathered to make adjustments. There are an unlimited number of ways to identify a pitcher’s strengths and monitor progress, from high speed video, drawing lines on a baseball for spin axis and spin direction work, throwing hockey pucks or even something as simple as letting the pitcher find the feel that works for him by having the Rapsodo give him feedback. Every pitcher is different and there are no absolutes when it comes to designing pitches. Find what works best and keep an open mind.

If you have any questions feel free to reach out to me on Twitter (@bomar19).

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