During the 2007 baseball season, Major League Baseball (MLB) began a systematic effort to record detailed information about the pitches that are thrown. All baseball stadiums were equipped with video cameras that would track each pitched ball and determine its precise trajectory. From the measurements made from the cameras, one is able to learn about the speed of each pitch at its release point and at the point where it reaches home plate. Also one can measure the amount and angle of the movement of the pitch in the path from the pitcher’s release point to crossing the plate. This technology is known as the PITCHf/x system. A good introduction to the PITCHf/x system and the associated variables is given in Fast (2010).