Invariant variables in coaching of pitching: extracting experiential knowledge from expert coaches

Abstract

This study was conducted to obtain some invariant variables in coaching of pitching from seven expert coaches and four former professional baseball pitchers. They were requested to expound their views on movement of pitching of some pitchers who was videotaped, and answered questionnaire on movement of pitching and psychometric tests by means of a paired comparison method using computer graphics. The followings were representative of invariant variables: 1) whole body coordination including rhythm and timing, 2) pressing and twisting of standing leg, 3) weight shift, 4) pelvis and trunk rotation during transfer phase from linear movement to rotational movement 5) movement and trajectory of throwing arm. Expert high school coaches more paid attention to the throwing arm. On the other hand, the former professional baseball players more paid attention to the trunk and the lower extremities. On shoulder horizontal abduction/adduction during take-back phase, both groups had different opinion.