Author(s): WU, H., CHEN, C.L., HSIEH, T.Y., Institution: FU JEN CATHOLIC UNIVERSITY, Country: TAIWAN, Abstract-ID: 892

INTRODUCTION:
The early pickup of task-relevant informational cues from the pitcher is a decisive factor in enhancing batting performance outcomes. An observer’s ability to accurately extract task-relevant kinematic features from a pitching pattern is constrained by affordances shaped through sport-specific expertise. Previous research has demonstrated that invariants of pitching coordination patterns are perceptually available, highlighting the visual system’s sensitivity to the structural properties of biological motion. This experiment examined perceptual performance in identifying different pitching patterns across baseball skill levels.
METHODS:
Thirty-six participants were recruited, including 12 Division I collegiate pitchers, 12 Division I field players, and 12 individuals without formal baseball training. Biological motion videos were obtained from two Division I pitchers (one left-handed and one right-handed) by manually digitizing 13 anatomical landmarks using Tracker software. Point-light displays representing fastball and breaking-ball deliveries, as well as strike and ball outcomes, were generated and presented in a randomized order. Participants identified pitch type, pitch location, and pitcher handedness. Recognition accuracy was evaluated using one-sample t-tests against chance level (0.5), and group differences were conducted by using Welch’s one-way ANOVA.
RESULTS:
The results showed that accuracy rates for all three groups were significantly higher than the random guessing probability of 0.5 (ps < .001). ANOVA indicated significant differences in accuracy rates for identifying handedness and pitching type among the three groups, where pitchers and fielders were significantly higher than individuals (ps < .001). No significant differences were found among the groups for strike/ball recognition.
CONCLUSION:
This study found significant differences among individuals with varying levels of expertise in identifying pitcher handedness and pitching types using dynamic point-light displays. The results demonstrate that biological motion serves as a vital tool for verifying the existence of informational invariants and examining affordances. Although mirror flipping alters the pitcher’s structural orientation and spatial coordinates, the relative motion between joints remains unchanged. These findings suggest that professional sports expertise arises from the integration of physical performance and sport-specific perceptual abilities, as kinematic information structures invariant cues that specify motion identity regardless of spatial orientation.
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