发表机构
Bowling Green State University（鲍灵格林州立大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
将打击率分解为避三振率与完成率的乘积，发现避三振高度可重复而完成率噪声大，且二者天赋负相关增强，解释了.400打击手的消失。
AI 中文摘要
打击率可精确分解为 BA = c × f，其中 c = (AB - SO)/AB 是避免被三振的比率，f = H/(AB - SO) 是非三振打席转化为安打的比率。利用2025年至少拥有300个打席的256名大联盟击球手，我们表明这两个因素的行为截然不同。避免三振的能力高度可重复，在2004年至2025年的19个连续赛季配对中，其逐年相关系数的中位数为0.86。完成率则不然：其相关系数的中位数为0.44，而打击率本身（0.44）的可重复性并不高于其噪声更大的因素。对2025赛季拟合的双变量logistic-normal随机效应模型估计两种天赋之间的相关性为-0.68（95%轮廓区间为-0.85至-0.50），远强于原始相关性-0.44，并暗示c的单赛季信度为0.91，f为0.37。该模型还产生了一个闭式双变量收缩估计量，其中击球手的三振率为其完成率的估计提供信息。应用于数十年的美国联盟和国家联盟数据，该分解重新审视了古尔德对.400打击手消失的解释。自死球时代以来，避免三振的天赋方差增长了约4.6倍，而完成率的天赋方差则减半，且两者之间的相关性从接近零变为约-0.53。这种新兴的权衡，而非天赋的普遍收窄，解释了现代打击率分布收窄的原因。
英文摘要
Batting average factors exactly as BA = c times f, where c = (AB - SO)/AB is the rate of avoiding a strikeout and f = H/(AB - SO) is the rate at which non-strikeout at-bats become hits. Using the 256 major-league hitters with at least 300 at-bats in 2025, we show that the two factors behave very differently. Strikeout avoidance is highly repeatable, with a median year-to-year correlation of 0.86 over 19 consecutive-season pairs from 2004 to 2025. The finishing rate is not: its median correlation is 0.44, and batting average itself (0.44) is no more repeatable than its noisier factor. A bivariate logistic-normal random-effects model fit to the 2025 season estimates the correlation between the two talents at -0.68 (95\% profile interval -0.85 to -0.50), far stronger than the raw correlation of -0.44, and implies single-season reliabilities of 0.91 for c and 0.37 for f. The model also yields a closed-form bivariate shrinkage estimator in which a hitter's strikeout rate informs the estimate of his finishing rate. Applied to decades of American and National League data, the decomposition revisits Gould's explanation for the disappearance of the .400 hitter. Since the dead-ball era, the talent variance of strikeout avoidance has grown roughly 4.6-fold while that of finishing has halved, and the correlation between them has moved from near zero to about -0.53. That emerging trade-off, rather than a general narrowing of talent, accounts for the reduced spread of modern batting averages.
