Prep Baseball Report

PBR Utah - Trackman Information Guide

Jeff Scholzen
Utah Scouting Director

Trackman Information Guide

For several years now baseball has been shifting towards an era in which data is instrumental in everything we do. It drives decision making on Major League diamonds, as well as that of free agent signings, draft picks, and other aspects within a front office. But most importantly, especially for Prep Baseball Report, it drives player development and how we evaluate talent. 

Leading the new data driven era is a device called Trackman. It is currently situated in all Major League ballparks as well as most, if not all, Minor League ballparks - from the Rookie level to Triple-A. The main function of Trackman is to relay pitching and hitting data to scouts and coaches which will allow them to evaluate the player accordingly. This technology can track upwards of 27 different measurements per hit/pitch.

Throughout the current year, Prep Baseball Report Utah will be highlighting players that stood out among the rest this past season, when it comes to the data Trackman provides. We will cover metrics that make that player a threat to the opposition as well as areas where we think this player can become more efficient and successful. Before we begin to analyze those specific players, it is important we go over what these metrics are and why they are important. First, let’s cover the pitching side of things:


Spin Rate
Spin rate is how many revolutions per minute (RPM) a ball makes when released from a pitcher’s hand. Now although spin rate is important, it is not the be-all end-all. The ability to spin the ball is a talent and not everyone can do it. A pitcher can still be very effective with a lower spin rate, it is all dependent on the type of repertoire the pitcher possesses.  

Having a higher spin rate does not necessarily mean that pitch will be effective or have elite movement. There are other aspects that come into play, such as Active Spin Ratio (ASR). ASR is the percentage of spin on a pitch that contributes to the movement of the pitch. A pitch could have a spin rate of 2500 but have an ASR of 50%. A low ASR is not necessarily a bad thing. For example, a slider can be very effective with a low ASR.

Having a high spin rate can be very effective if used correctly. One way a high spin rate can be used effectively is to create steeper angles on breaking balls. However, this also requires a high ASR.

Tilt (or Spin Axis)
Tilt is spin axis converted into clock time, rounded to the nearest 15 minutes. A ball always breaks towards the number on the clock face:

  • 6:00 is perfect top spin (12/6 curveball), causing the ball to break down.

  • 12:00 is perfect back spin (a true 4-seam fastball) causing the ball to break upward relative to how it would have moved if gravity were the only factor. 

  • 3:00 is a frisbee slider thrown by a LHP spinning and breaking to the right.

Here’s an example of how it looks on a clock for a RHP (black is the fastball, blue is the slider):

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Induced Vertical Break (IVB) and Horizontal Break (HB)
Induced Vertical Break, or IVB, is the distance measured in inches between where the ball crosses the plate on a vertical axis, compared to where it would have crossed had it travelled in a straight line from release and been affected by gravity. As aforementioned, spin rate is important. But when it comes to the fastball, IVB is a more valuable statistic than spin rate. It is a better indicator of where a pitcher should be locating their fastball. 

Horizontal Break, or HB, is the distance measured in inches between where the pitch crosses the front of home plate on a horizontal axis, and where it would have crossed if it had travelled in a perfectly straight line out of the pitcher’s hand. A positive HB means the break is to the right from the pitcher’s perspective, while a negative number means it is to the left. It stays the same for both right-handed and left-handed pitchers.

Gyroscopic Spin (Gyro Spin)
When you throw a football, think about how it is spinning; that is Gyro Spin. When a pitch has 100% gyro spin, there is no change to the movement of the ball due to the lack of magnus force. The only movement on that pitch is the effect gravity has on it. With all other spin axis’, there is magnus force involved. 

Now although Trackman does not tell us what the Gyro Spin on a pitch is, it is important to understand the concept because it can be applied to other pitches as well. For example, if gyro spin is applied to a changeup, it will decrease the Induced Vertical Break on that pitch thus making it more effective as it will differ from the pitcher’s fastball.

Release Height and Release Side
These two metrics are easy to understand but play a pivotal role in disguising your repertoire and tunneling your pitches.

Release Height is how high above home plate the ball is when released by the pitcher, measured in feet. This is important when looking at how a player tunnels their pitches as well as when looking at aspects of the ball’s flight.

Release side is how far to the left or right of the rubber, depending on handedness, the ball is when released by the pitcher. From the pitcher’s perspective, baseballs released on the right side have a positive number, while the left side has a negative number. Just like release height, this too has an impact on the player’s pitch tunneling ability and ball flight.

Although it is not crucial, it is beneficial to have a similar release height and side for all your pitches. This makes it more difficult for a batter to identify the pitch out of your hand as they are all coming out of the same arm slot.

Extension is another one of those metrics that is easy to comprehend but is very important. It is how far down the mound from the rubber, in feet, the pitcher releases the ball. This statistic is important for a couple reasons. It directly affects a pitcher’s VAA (discussed below) as well as a pitcher’s repertoire. It is vital that a pitcher have a similar extension on all their pitches to disguise them, just as discussed with release height and side.

For example, if a pitcher throws a curveball but does not extend as far as they would on their fastball, they may create a little “hump” in the ball’s path towards the plate which will make the curveball easily identifiable for a quality hitter.

Vertical Approach Angle (VAA)
Vertical Approach Angle is the angle at which the ball crosses the front of the plate. A negative number means the ball is angled towards the ground. The chart below shows us the different VAAs and the outcomes they produce in the MLB:

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There is no such thing as a poor VAA. However, there is such a thing as a poor VAA at the top of the zone. This just means that you should be locating your fastball down in the zone. The same applies for a poor VAA down in the zone. The general rule to follow regarding VAA is that a fastball with a steeper VAA should be located at the bottom of the zone, while one with a flatter VAA should be located up in the zone. There is a very high correlation between “flat” fastballs up in the zone and WHIFF%. The same goes for “steep” fastballs down in the zone, WHIFF% increases along with GB%. It is also important to remember that a fastball from the same pitcher up in the zone will have a drastically different VAA then a fastball down in the zone.

For the most part, a pitcher’s VAA is determined by their extension and release height. A longer extension and lower release height will lead to a flatter VAA while a shorter extension and higher release height will do the opposite. These factors can be manipulated to change your VAA.

While VAA is important, it is not the end-all be-all metric. It is important to continuously mix up your fastball location to avoid becoming predictable regardless of your VAA.


Unlike pitching metrics, the statistics Trackman produces for hitters are far easier to understand and there are not as many. When looking at Trackman hitter’s numbers, we tend to focus on a select few. These include: 

  • Exit Velocity (EV)
  • Launch Angle (LA)
  • Sweet Spot %
  • Direction

The only statistic of those that needs some explanation is Sweet Spot %. Sweet Spot % is the percentage of batted balls between 8 and 32 degrees. As well, while we all know what LA is, it is important to know what each LA is classified as:

  • Less than 10 degrees – Ground ball
  • 10 – 25 degrees – Line drive
  • 25 – 50 degrees – Fly ball
  • Greater than 50 degrees – Pop up

A LA hitter will depend on the type of hitter they are. If they have more of a contact approach, they’ll be looking for line drives all day, while a hitter with some pop will be looking to get the ball in the air.