Biggest difference between the two systems was found in measurements
of pitch speed. There have been notable disparities in pitch speed reports
between 2016 and 2017. Official pitch speed readings were based on
velocity from the release of the pitch, rather than the speed measured 50
feet from home plate before substitution of Trackman.^7
As mentioned before, every pitch forms a curve until it reaches the home
plate. Also, we discovered that depending on which point of the curve
we measure the velocity, we will get different results. So the velocity can
be recorded differently. depending on where the radar is tracking
between the release point and the home plate.
The moment a baseball leaves a pitcher’s hand, it starts to slow down
because of drag force. According to University of Illinois physicist Dr.
Alan Nathan, a pitch that leaves a pitcher’s hand at 100 mph will (at sea
level) slow down by 9 to 10% by the time it crosses the plate some 55-58
feet later (average release point)^7
So that 100 mph pitch could be measured at 100 mph (at the pitcher’s
hand), 99 mph (at 50 feet from home plate), 94 mph (midway on its
journey) or 91 mph (as it crosses home plate). The rate of decrease varies
based on atmospheric pressure, which was why Coors Field had a high
speed of pitch.^7
Statcast is mainly divided into two systems: a radar system, which detects
ball movement, and a camera system, which detects players movement. A
radar system is powered by Trackman, and a camera system is developed
by Chyronhego. All the measurements we discussed in this chapter is
collected by Trackman; it basically measures all the movements of a ball,