Major League Baseball (MLB) has started its 3 year experiment in the minor leagues that will see the introduction of a Trackman computer system that uses Doppler Radar to accurately track balls and strikes. Plate umpires wearing earpieces will be informed of ball/strike calls by the computer. The umpires can overrule the computer, but some are wary of earlier attempts of introducing a tracking system. Umpires have been evaluated by the Trackman system since 2017. West, who has umpired more than 5,000 big league games and is on track to break Bill Klem's record in 2020, said the 2016 test was far from perfect. "It missed 500 pitches in April, and when I say it missed 500 pitches, that didn't mean they called them wrong. They didn't call them at all," he said.