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. 

FASTBALL INDUCED VERTICAL BREAK

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. 

BREAKINGBALL SPIN RATE

Spin rate on breakingballs 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 breakingball is, but it can also aid in keeping hitters honest by having similar rotation matching that of your fastball.