Rob Gray is an associate professor and program head of the human systems engineering program at Arizona State University, USA. He has published more than 25 research articles on baseball. He is also host and producer of the popular Perception & Action podcast. Randy Sullivan is a physical therapist, a baseball coach, and a certified strength and conditioning specialist. He has been the owner and director of the Florida Baseball ARMory training facility, and a paid consultant to MLB and collegiate baseball programs for more than 25 years.