Understanding Rapsodo Pitching Data: Velocity & Release Profile

Velocity

Velocity: the singular measurement by which all pitchers have been assessed over the course of baseball history. It gauges the release speed of the ball as it leaves a pitcher’s hand.  

It goes without saying that pitches thrown at higher velocity ranges have more room for location error, especially when it comes to fastballs. However, pure velocity is only one measure by which pitchers can evaluate their development. While higher velocities directly shorten the length of time a hitter has to react to the pitch, being able to widen a pitcher’s velocity ranges will allow the pitcher to keep hitters off-balance. 

When measuring velocity, benchmarks should be measured against a pitcher’s fastest pitch, typically some variation of a fastball. At the Major League level

  • The average four-seam, two-seam/sinker, and cut fastball velocities are 93.4, 92.7, and 88.5 mph, respectively. 
  • Off-speed pitches typically show a velocity variance of about 8-12 mph slower than the pitcher’s average fastball velocity; changeups and splitters average 84.5 and 85.2 mph.  
  • Traditional breaking pitches such as curveballs and sliders can vary anywhere between 7-15 mph below average fastball velocity, depending on pitch type; curveballs and sliders average 78.5 and 84.7 mph. 

Release Profile

A given pitcher’s release point can heavily dictate what combination of pitches will allow them to be most effective against hitters. Due to the intricacies present in a given pitcher’s release, Rapsodo measures four distinct variables of release: 

  • Release height is measured as the vertical distance, in feet, between home plate and the pitcher’s vertical release point. 
  • Release side is measured as the horizontal distance, in feet, between the center of the pitching rubber to the pitcher’s horizontal release point. It is important to remember that this distance can vary based on where the pitcher sets up on the rubber.  
  • Release angle measures the vertical degree of the ball as the pitcher is releasing it; negative angles indicate a downward trajectory, while positive angles indicate upward trajectory. 
  • Horizontal angle, similar to release angle, measures the horizontal degree of the ball at release; negative angles indicate a trajectory to the left, while positive angles indicate a trajectory to the right.