GLOSSARY OF TERMS VIA TRACKMAN:

Release Speed:

Speed of pitch, reported in miles per hour, when it leaves the pitcher’s hand.

Spin Rate:

How fast the ball is spinning as it leaves the pitcher’s hand, reported in the number of times the pitched ball would spin per minute (“revolutions per minute” or “rpm”).

Induced Vertical Break:

Distance, measured in inches, between where the pitch actually crosses the front of home plate height-wise, and where it would have crossed home plate height-wise if had it traveled in a perfectly straight line from release, but affected by gravity. 

Bauer Units:

Take average spin and divide by average velocity. Higher the Bauer Units the more efficient your velocity is. This means a pitcher that gets a lot of swing and misses at top of zone would more than likely have a high Bauer Unit as the velocity is efficient.

Release Height:

Height, reported in feet, above home plate at which the pitcher releases the ball.

Horizontal Break:

 Distance, measured in inches, between where the pitch actually crosses the front of home plate side-wise, and where it would have crossed home plate side-wise if had it traveled in a perfectly straight line from release. A positive number means the break was to the right from the pitcher’s perspective, while a negative number means the break was to the left from the pitcher’s perspective.

Extension:

The distance, reported in feet, from which the pitcher releases the ball relative to the pitching rubber.