The "Pitch-f/x" value is currently defined as the measurement of the distance between the location of the actual pitch thrown over the plate, and the calculated location of a ball thrown by the pitcher in the same way, with no spin; this is the value we provided in Enhanced Gameday last season as "Break". The new Break value, which we feel is more appropriate for the common understanding of the term, is defined as the measurement of the greatest distance between the trajectory of the pitch at any point between the release point and the front of home plate, and the straight line path from the release point and the front of home plate. By this definition, a Barry Zito curveball will have a much greater Break value than a Brad Penny fastball.
(By the way, the "camera control" in the 3D batter area allows you to view each pitch from any of six different viewpoints, so you can see the trajectory and location of each pitch from multiple angles.)
I have no idea what that really means though...i got it off google