  This manuscript is a statistical investigation into the 2017 Major League
Baseball scandal involving the Houston Astros, the World Series championship
winner that 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 manuscript are: 1) 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, 2) 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 3) 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.
