Welcome back to Trackman Traits! We will be dissecting the numbers the Trackman produces and the effect they can have on a pitcher's approach. Below are 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

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.

FASTBALL SPIN RATE

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

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. 

FASTBALL INDUCED VERTICAL BREAK

As far as deception goes, induced vertical break (IVB) is one of the more important metrics. 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. 

VERTICAL APPROACH ANGLE

One of the newer metrics we have begun to look at when evaluating FBs, vertical approach angle (VAA) can be a key indicator for swing and misses on FBs, especially when located in the top of the zone. Pitchers with lower numbers in this category have FBs that approach the plate at a more "shallow" angle, making that FB appear to have ride through the top of the zone and tougher to barrel up. Pitchers with higher numbers in this metric have "steeper" approach angles, making for a more heavy FB that should induce plenty of ground balls. Like with some of the above metrics, this is one to steer clear of being average in. VAA, like IVB, can be tweaked a bit with differing release heights. The top 10% VAA (more shallow) among D1 pitchers sits at -3.5 degrees, and the bottom 10% (more steep) among D1 pitchers is -7.5 degrees with the average VAA sitting at -5.6 degrees.

 

 

 

 

Velocity: As a high school senior, Semon sees himself with top-end velocity for a high school arm, with his best FB hitting 89.23. That would put him in the top 10 percentile for high school pitchers. When looking ahead, however, we see Semon’s FB velocity would put him right around average at the college level. Being average in the velocity category isn’t the worst category to be average in though and he should still find his FB to be plenty effective, it just leaves a slightly smaller margin for error in location. 

Spin Rate: This is another category that Semon finds himself above average in currently as a high school arm. His max spin rate of 2324 RPM is pretty high end spin for high school FBs and the average spin still ranks as slightly above average at the high school level, but will find himself creeping closer to college averages when he reaches that level. Spin is one of those areas we want to stray away from average, but for now, Semon’s FB should still play up thanks to that spin. 

Bauer Units: When talking about FB spin, I think it’s important to bring up Bauer Units as a way of comparing multiple different FBs on the same playing field. As velocity goes up on your FB, spin tends to follow, so this metric is helpful when comparing spin numbers on FBs with different velocities. The average number in this category is 23, and Semon finds himself at 26, well above the average and a sign pointing to his FB playing up in the zone well. For reference, some MLB starters with Bauer Units of 26 on their FB include Gerrit Cole, Yu Darvish, and Lucas Giolito, just to name a few. Guys like Cole and Giolito like to attack hitters north/south and will elevate their heaters up in the zone for swings and misses, especially when they’re ahead in counts.

Induced Vertical Break: Where the advanced spin and Bauer Units tell a story of a FB that could see success up in the zone, the IVB tells somewhat of a different story. Ideally, guys with FBs that attack up in the zone have IVBs that are in the top 25 percentile of their playing level. Guys with higher IVB numbers have that “ride” through the zone or that extra little hump on it that helps their FB miss barrels at the top of the zone. With Semon, his max IVB was 17.8 and his average IVB was 15.1, numbers that would put him closer to the high school averages. Among college arms, that max IVB is nearing the top 25%, but still just a bit below.

Vertical Approach Angle: Semon’s average vertical approach angle sits at -5.2 degrees, or just around the average for D1 pitchers at -5.6 degrees. Another category you don’t want to be around the average in, Semon had some variability in his VAA pitch-to-pitch. VAA is a number that is reliant on release point and pitch location, so if there are inconsistencies in those areas, it could cause inconsistent VAA numbers as well. On some of Semon’s FB thrown just above the zone, we saw a VAA of -3.6 degrees and -4.3 degrees, numbers that would support pitching up in the zone. On the contrary, though, some FBs down saw VAA numbers in the -7 degree range, numbers that would support pitching down in the zone.

Recap: When it comes to game-planning for Semon and strategizing how to use his FB best, these numbers pull you in different directions. Some numbers like the Bauer Units suggest his FB could play well at the top of the zone and some numbers like IVB point to a FB that might get a hit a little bit harder than it should when left up in the zone. Before making the final call on Semon, I would want to see some more data from a larger sample and how his off-speed played off the FB before truly determining whether or not he should be attacking up or down with his FB. Generally speaking, pitching down in the zone is the safe route for most pitchers, so I would advise to probably live at the knees. I do believe that there are some up-in-the-zone capabilities present, the velocity and spin combo can miss bats and the Bauer Units suggest FBs up should be effective up. I would say since the rest of the metrics tell a slightly different story than those metrics though, the margin of error for the elevated FB would be slimmer for Semon than for others, so more precise location would be key and making sure that FB stays above the barrels of hitters to generate swings and misses.

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