Trackman Traits - Pitching: 2021 LHP Sam Thompson (St. Xavier HS/Marshall Commit)

Zach Guth
KY Contributor/PA-NY Advanced Scout

Welcome to Trackman Traits! In this piece we will be dissecting the numbers the Trackman produces and the effect they can have on a pitcher's approach. Below there will be definitions of each category that we believe to be the most important for a young arm to keep in mind as well as breaking down an arm and giving suggestions on how they can improve their game. Keep in mind, in some categories it is better to be further away from average even if the numbers are wavering on below average. 


Fastball velocity doesn't go much deeper than just looking at the numbers and comparing them to the graphic below! Fastball velocity complements just about all of the other metrics that are measured. If you throw hard, it makes all your other pitches/metrics even better.


Spin rate is a measurement that if you are below average or above average, you can pitch with more room for error. On the other hand, if you are average you should try to throw in the bottom half of the zone with exceptional command. High spin fastballs profile as one that is frequently described as having "late life". Low spin fastballs tend to profile as a fastball that has heavy feel to it. Pitch movement is still dependent on spin direction of the pitch but Trackman does not have that metric displayed on profiles. 


Bauer Units are an easier way of determining how useful the spin numbers are compared to the velocity. We can calculate this metric by taking average spin rate and dividing it by average velocity. Bauer Units are useful because we can have a case of two pitchers with the same spin numbers, ex. 2200 RPM, but one pitcher throws 90 MPH and the other throws 83 MPH. The pitcher throwing 90 MPH with 2200 spin is not as impressive as the pitcher throwing 83 MPH with the same spin. Typically, we would tell the harder throwing pitcher to throw up in the zone purely off his velocity and his high spin, but because his Bauer Units would equate to around 24 that would be only 1 unit off of average (23), therefore he would want to hammer the bottom of the zone. On the other side, the pitcher throwing 83 MPH has a Bauer Unit measurement of 26 which is incredibly impressive. This would allow him to throw up in the zone even though his velocity is not blow away type numbers because he produces above average spin with that slated velocity. 


As far as deception and importance goes, fast induced vertical break (IVB) may be the most important. Induced vertical break is not what is sounds. IVB simply means the pitch is "breaking" upward from the average level a pitch falls from release to home plate. This is a stat that you want to stay away from being average at. Fortunately, this can be tweaked slightly depending on release height. To put it simply, the higher number =  more "rise" the pitch has compared to average. Lower number = more depth the pitch has to it. 


Spin rate on curveballs is pretty simple: higher spin = nastier stuff. There are some ways to manipulate spin numbers slightly but for the most part spin is spin. At the moment, there are no well known ways to change your spin in a big way. Spin not only dictates how sharp your curveball is, but it can also aid in keeping hitters honest by having similar rotation matching that of your fastball. 



Sam Thompson

Class of 2021 / LHP

Player Information

  • Graduating Class: 2021
  • Primary Position: LHP
    Secondary Position: OF
  • High School: St. Xavier
    State: KY
  • Summer Team: Legends
  • Height: 6-2
    Weight: 175lbs
  • Bat/Throw: L/L

Scouting Report



Thompson showed his best velocity to date working 82-85 and touching 86 with arm-side run. The 6-foot-1, 175 pound lefty also showed a late-breaking 76-77 slider and feel for 76-79 chengeup. He has an athletic 6-foot-1, 175 pound frame, and has long/loose arm action and easy velocity suggest there is more velocity coming. One of the top uncommitted LHP's in the 2021 class.
Spin rates: FB up to 2299, Slider up to 2597



Fastball Breakdown

Velocity: Thompson maintains solid velocity for a high school arm. A plus for him is the fact that he is left handed. Left handed arms have a slightly advantage where velocity does not have to be as high for them to get recruited. Seeing as how 85 MPH falls in the top 25% among all high schoolers, Thompson is in a good spot. Marshall has taken notice and that is why he will be in their incoming recruiting class in Fall '21. 

Spin Rate (SR): With some exceptional spin, Thompson creates the opportunity for the ball flight to be flatter with more hop. The one thing moment depends on is tilt. Tilt is the orientation of how the pitch is spinning on its way to home plate. Taking a look at his movement numbers, it is evident that he induces some significant tilt on his pitch. With the top of the line spin, it plays a big part of how much the pitch is moving. 

Bauer Units: Bauer Units are valuable in the evaluation of if the spin is good for the level of velocity. Falling in around 27 units, it is apparent that Thompson creates some really good spin for his velocity. His spin is well above the typical amount for his velocity. This usually means that there could be an uptick in velocity coming soon or there is a leak in velo somewhere within his mechanics. 

Induced Vertical Break (IVB): The most impressive part about Thompson's skill set is his ability to induce movement on his fastball. Coming in with around 10" of IVB it means that the ball is coming in with significantly more depth that a normal fastball would. To put it into perspective, "average" IVB is somewhere around 18". With 10" being Thompson's average, a hitter is not used to seeing this type of depth on a pitch. Not only is the ball sinking, but it is running to his arm side around 4.8". This isn't a mind-blowing amount of movement, but the maximum HM at 15" is the impressive one. This pitch is running and diving away from a RHH and into a LHH. This is what most hitters would classify as a filthy heater. 

Slider Breakdown

Spin Rate (SR): Seeing as how Thompson averages around 2507 RPM on his slider he is is throwing it with the same conviction as his fastball. Throwing off speed pitches with high spin is also something you want, except for the case of changeup type pitches. The spin he possess on his slider slots it above the top 10% among high school sliders. With 34 Bauer Units, it appears that there is room for the velocity to come in. If this ends up happening, the pitch could become a top notch swing and miss pitch. 

Horizontal/Vertical Break: When we look at horizontal movement (HM) you want to think about it on a number line scale from the pitcher's view to home. At pitcher's mound, the measurement would be zero if someone threw a pitch that didn't move to either side. If a pitch moves to the left, it is a negative number and if a pitch moves to the right it would be a positive number. When a slider has a negative number it means is has some vertical depth to it. When we pair this with the horizontal movement coming in around 4.2" is a quality pitch. This pitch would be best thrown down in the zone and into the deadzone of a RHH. One more thing Thompson has going for him is his deceptiveness. He releases both pitches with 6' extension and 6' release height. With both pitches coming from this slot and similar arm speeds, it makes Thompson a deceptive lefty. Who doesn't want a deceptive lefty in their starting/bullpen rotation?  


Louisville Preseason ID Showcase 1-23-21 KY 01/23 Legends Sports Academy
PBR Kentucky Introduction To Showcases 1-23-21 KY 01/23 Legends Sports Academy
Western Kentucky Prospect ID Showcase 1-24-21 KY 01/24 Planters Bank - Jennie Stuart Sportsplex
Preseason All-State Showcase 2-6-21 Invite Only (Class of 2023-2024) KY 02/06 Champions Sports
Preseason All-State Showcase 2-7-21 Invite Only (Class of 2021-2022) KY 02/07 Champions Sports
Super 60 Pro Showcase NATIONAL 02/07 MOSH Performance Center