PITCHf/x is a pitch tracking system, created by Sportvision, and is installed in every MLB stadium since around 2006. This system tracks the velocity, movement, release point, spin, and pitch location for every pitch thrown in baseball, allowing pitches and pitchers to be analyzed and compared at a detailed level. Two mounted cameras in each stadium are used to track each pitch and establish the each aforementioned aspect.
What sort of separation in movement Zack Grienke does get with his pitches? Did Andy Sonnanstine change his release point at some point during the season? Which pitcher had the most break on their curveball? These are just a sample of the multiple questions you can answer using PITCHF/x data. The possibilities are nearly endless.
If you use MLB’s Gameday, then you have already seen live PITCHf/x data first hand. There are many different websites and resources for PITCHf/x, including right here at FanGraphs.
To learn more about PITCHF/x, please see the other pages about it in the Library: