This study evaluated baseball pitching accuracy using a variety of parameters to quantify pitching errors and analysed the validity of the accuracy measurements by comparing the outcomes of two small groups of pitchers. Several professional (n = 5) and high school (n = 8) pitchers threw 30 pitches each, including 20 fastballs and 10 breaking balls. To assess pitching accuracy, pitch locations relative to the catcher's mitt (as the target) were evaluated with various parameters, including major/minor radius, an area of 95% confidence ellipse, absolute error, constant error and pitch location trajectory. Compared to the high school pitchers, the professional pitchers exhibited shorter major and minor radii in their 20 fastball pitches (p < 0.05), more accurate control in the lateral direction (p < 0.05), and shorter pitch location trajectories (p < 0.05). The evaluation methods presented in this study can objectively assess pitching accuracy and may thus provide useful coaching feedback with visual information.
Keywords: Motor development; assessment; feedback; motor control; throwing.