Sphere Passing Through Indicating Fence Applied In Senior High School Baseball Player Batting Test: An Exploratory Two-Case Pilot Study

Purpose: A fence to indicate sphere passing through (id-f) was designed to let baseball players transit between fixate on the baseball and initiating their swing clearly. In addition, the acute effects of this id-f on player's batting performance were studied. Method: A non-elite player (NEP) with no experience in the national senior high school baseball competition and an elite player (EP) with best batting average (0.324) in competitions were recruited as the subjects. In the experiment, a pitching machine was used to throw 130 km/hr fastballs, and the subjects underwent Test A, Test B, and Test C in sequence. The Swing Analyzer was used to analyze the bat speeds and peak hand speeds during the swings, and the number of effective strikes were also recorded. Result: Compared to Test A, which did not involve the use of id-f during baseball fixation exercises and batting testing, Test B incorporated id-f. In Test B, NEP demonstrated higher bat speed and a greater number of effective strikes than in Test A. However, EP exhibited only a greater number of effective strikes compared to Test A. In Test C, baseball fixation exercises were omitted, and batting testing was conducted directly without id-f. In this test, NEP again demonstrated higher bat speed and a greater number of effective strikes than in Test A. Nevertheless, EP exhibited only a greater number of effective strikes compared to Test A. Conclusion: This study examined the acute effects of the id-f system on batting performance in novice (NEP) and experienced (EP) high school baseball players. Under consistent pitching conditions, id-f significantly improved bat speed in NEP, likely due to earlier swing initiation via visual feedback. EP, while showing no bat speed gains, achieved more effective strikes later in testing. Peak hand speed remained unchanged, suggesting id-f’s influence was specific to the bat’s distal end. However, potential practice effects from repeated testing may have confounded the results. Future research should use randomized test orders, control groups, and larger samples to better isolate id-f’s effects.