Department of Sports Research, Japan Institute of Sports Sciences, Kita-ku, Tokyo, Japan.
College of Systems Engineering and Science, Shibaura Institute of Technology, Saitama, Saitama, Japan.
PLoS One. 2020 Mar 17;15(3):e0230385. doi: 10.1371/journal.pone.0230385. eCollection 2020.
Baseball pitchers use various pitch types to reduce hitting accuracy, but little is understood of the practical strategy of using visuomotor skills and timing control to respond to different pitches. This study examined 1) effectiveness of pitch type combinations, and 2) relationship between the presence and absence of advance information about the next pitch and the timing error. Twenty-six high school baseball players hit a ball launched from a pitching machine in a combination of fastballs (34.3±1.3 m·s-1), curveballs (25.4±1.0 m·s-1), and slowballs (25.5±0.9 m·s-1). Each participant performed three conditions. (1) Continuity condition (15 trials), in which the same pitch type was thrown five times consecutively. (2) Random condition (30 trials), in which pitch type was not preliminarily conveyed to the participants. (3) Open condition (20 trials), in which the next pitch type was preliminarily conveyed to participants. Participants' hitting movement was recorded by an optical motion capture system and force platform. We calculated timing error based on the difference between the measured impact location (ball position relative to the batter's body at ball-bat impact) and optimal impact location. The timing error between n-th pitch type, (n-1)-th pitch, and the presence or absence of advance information about pitch type (open vs random condition) were analyzed using three-way repeated ANOVA. The results showed that the (n-1)-th pitch type did not affect the timing of impact (p = 0.338). In contrast, the timing errors in open conditions were fewer compared to random conditions (p < 0.001). These results indicate that the pitch type sequence has insignificant effects, and advance information about pitches affects the timing errors. Therefore, having two or more pitch types, reducing the fluctuation of the pitching motion, and the early trajectory of the ball between different pitches potentially lead to increase timing errors.
棒球投手使用各种投球类型来降低击球准确性，但对于利用运动知觉技能和时间控制来应对不同投球的实际策略知之甚少。本研究考察了 1）投球类型组合的效果，和 2）下一个投球的提前信息的存在与否与时间误差之间的关系。26 名高中棒球运动员从投球机中击出球，投球类型分别为快球（34.3±1.3 m·s-1）、曲线球（25.4±1.0 m·s-1）和慢球（25.5±0.9 m·s-1）。每个参与者完成三种条件。（1）连续条件（15 次试投），连续投出 5 次相同的投球类型。（2）随机条件（30 次试投），不给参与者预先传达投球类型。（3）开放条件（20 次试投），提前向参与者传达下一个投球类型。参与者的击球动作由光学运动捕捉系统和力平台记录。我们根据测量的撞击位置（球相对于击球手身体在球棒撞击时的位置）和最佳撞击位置之间的差异计算时间误差。使用三向重复方差分析分析第 n 次投球类型、第（n-1）次投球类型以及下一个投球类型的提前信息（开放条件与随机条件）之间的时间误差。结果表明，（n-1）次投球类型不会影响撞击时间（p = 0.338）。相比之下，开放条件下的时间误差比随机条件下少（p < 0.001）。这些结果表明，投球类型序列没有显著影响，而关于投球的提前信息会影响时间误差。因此，拥有两种或更多的投球类型、减少投球动作的波动以及不同投球之间球的早期轨迹可能会导致时间误差增加。
