Abstract

This article is a statistical investigation into the 2017 Major League Baseball scandal involving the Houston Astros, the World Series championship winner that the same year. The Astros were alleged to have stolen their opponents’ pitching signs in order to provide their batters with a potentially unfair advantage. This work finds compelling evidence that the Astros on-field performance was significantly affected by their sign-stealing ploy and quantifies the effects. The three main findings in the article are (i) the Astros’ odds of swinging at a pitch were reduced by approximately 27% (OR: 0.725, 95% CI: (0.618, 0.850)) when the sign was stolen, (ii) when an Astros player swung, the odds of making contact with the ball increased roughly 80% (OR: 1.805, 95% CI: (1.342, 2.675)) on non-fastball pitches, and (iii) when the Astros made contact with a ball on a pitch in which the sign was known, the ball’s exit velocity (launch speed) increased on average by 2.386 (95% CI: (0.334, 4.451)) miles per hour.

摘要

本文是对 2017 年美国职业棒球大联盟丑闻的统计调查，该丑闻涉及同年世界系列赛冠军得主休斯顿太空人队。太空人被指控窃取了对手的投球标志，以便为他们的击球手提供潜在的不公平优势。这项工作找到了令人信服的证据，表明太空人队的场上表现受到他们的信号窃取策略的显着影响，并量化了这些影响。文章中的三个主要发现是 (i) 当标志被盗时，太空人队在球场上挥杆的几率降低了大约 27% (OR: 0.725, 95% CI: (0.618, 0.850))，(ii)当太空人队球员挥杆时，在非快球球场上与球接触的几率增加了大约 80% (OR: 1.805, 95% CI: (1.342, 2.675))，