Using Statistical Process Control Charts to Identify the Steroids Era in Major League Baseball: An Educational Exercise

This article presents an educational exercise in which statistical process control charts are constructed and used to identify the Steroids Era in American professional baseball. During this period (roughly 1993 until the present), numerous baseball players were alleged or proven to have used banned, performance-enhancing drugs. Also observed during this period was an increase in offensive performance. In this exercise, students are given the opportunity to construct trial control limits from historical data, consider the presence of random and assignable cause variation, and analyze offensive performance for the 1993 to 2008 baseball seasons. From this analysis, students can consider the potential impact of performance-enhancing drugs on offensive performance in Major League Baseball.