Being asked to give the Charles H. McCloy research lecture is one of the highlights of the author's academic career. Although McCloy's primary area of expertise was measurement and the analysis of motor skills, he also shared an avid interest in youth development through sport and physical activity. In this article, the author features youth sport…

To clarify patterns in the rate of motor development, children observed between kindergarten and second grade were refilmed, performing an overarm throw, when they became seventh-grade students. Results were compared with predictions made earlier. Differences in the skill levels of boys and girls and differences in their throwing experience are…