Abstract: Disclosed is a system for measuring a baseball or softball catcher's response, or “pop” time. The system includes a first sensor operable to detect a catcher catching a pitched ball, a second sensor operable to detect a baseman catching a ball thrown by the catcher, and a device with circuitry operable to calculate a pop time based on signals from the first and second sensors. Alternative embodiments allow measurement of time for a pitcher to deliver a pitch to the catcher, and other throwing and catching sequence metrics. Also disclosed are accompanying methods.