The increasing competitive balance in Major League Baseball

This paper explores the changing competitive balance in Major League Baseball through the relative-entropy measure of information theory. It is shown that while competitive balance in both leagues has been on an upward path during the 20th century, the path has had numerous detours that resulted from some on-the-field and some off-the-field changes that Major League Baseball has undergone during the past 75 years. The most important detours occurred in the wake of the Black Sox scandal of 1919, Jackie Robinson's breaking the color barrier and the concurrent spread of television and erosion of the minor leagues, franchise moves and major league expansion, and free agency.