Samborski S Andrew, ElAttrache Neal, Karnyski Steven, Bergeron Brooke, Ladnier Karen, Banffy Michael
Kerlan-Jobe Orthopaedic Clinic, Los Angeles, California, USA.
Orthop J Sports Med. 2025 Jun 27;13(6):23259671251346984. doi: 10.1177/23259671251346984. eCollection 2025 Jun.
Major League Baseball (MLB) implemented a new foreign substance policy in June 2021. The effect of the new policy on pitcher injuries, wild pitches, hit batters, and pitching statistics is unknown.
To determine the effect of the new foreign substance policy regarding grip enhancement before and after its implementation on pitcher injury rate, wild pitches, hit batters, base on balls, strikeouts (SO), and home runs (HR).
Descriptive epidemiology study.
MLB pitchers from the 2019 season were retrospectively compared with the pitchers from the 2022 season. Data were retrospectively collected on injuries and pitching statistics utilizing publicly available data. Primary outcome measures included pitcher injury rate, wild pitches, and hit batters. Secondary outcome measures included base on balls, SO, and HR. A nonparametric Wilcoxon rank-sum test was utilized for computing values when comparing unadjusted non-normally distributed continuous outcomes and covariates between 2019 and 2022, which was adjusted for number of batters faced using either a linear regression model for adjusting means or a quantile regression model for adjusting medians.
In total, 828 pitchers in the 2019 season and 867 pitchers in the 2022 season were evaluated and included in this analysis. Pitcher overall injury rate per 1000 batters faced, hit batters, and SO did not show a statistical difference ( > .05). There was a statistically significant decrease in the adjusted number of wild pitches (2.9 vs 2.51; .04), adjusted earned run average (ERA) (4.51 vs 3.75; < .01), adjusted base on balls (22.6 vs 21.1; .04), and adjusted HR (8.1 vs 6.1; < .01) between the 2019 and 2022 seasons ( < .05).
Our study showed that the effect of MLB policy enforcement regarding grip enhancement did not demonstrate a change in pitcher injury rate, hit batters, or SO; however, there was a significant decrease in wild pitches, ERA, and base on balls. As a result, the new policy appears to maintain previous injury rate and pitching statistics while attempting to control for foreign substance use.
美国职业棒球大联盟（MLB）于2021年6月实施了一项新的外来物质政策。该新政策对投手受伤情况、暴投、击球员被球击中以及投球数据的影响尚不清楚。
确定新的外来物质政策在实施前后对投手受伤率、暴投、击球员被球击中、保送、三振（SO）和本垒打（HR）方面抓握增强的影响。
描述性流行病学研究。
对2019赛季的MLB投手与2022赛季的投手进行回顾性比较。利用公开数据回顾性收集有关受伤情况和投球数据。主要观察指标包括投手受伤率、暴投和击球员被球击中。次要观察指标包括保送、三振和本垒打。在比较2019年和2022年未调整的非正态分布连续结果和协变量时，使用非参数威尔科克森秩和检验来计算P值，并使用线性回归模型调整均值或分位数回归模型调整中位数的方法，根据面对的击球员数量进行调整。
总共对2019赛季的828名投手和2022赛季的867名投手进行了评估并纳入本分析。每面对1000名击球员的投手总体受伤率、击球员被球击中以及三振情况均未显示出统计学差异（P>.05）。2019年和2022赛季之间，调整后的暴投次数（2.9对2.51；P=.04）、调整后的自责分率（ERA）（4.51对3.75；P<.01）、调整后的保送次数（22.6对21.1；P=.04）以及调整后的本垒打次数（8.1对6.1；P<.01）均有统计学显著下降（P<.05）。
我们的研究表明，MLB关于抓握增强的政策实施效果在投手受伤率、击球员被球击中或三振方面未显示出变化；然而，暴投、自责分率和保送次数有显著下降。因此，新政策似乎在维持先前的受伤率和投球数据的同时，试图控制外来物质的使用。
