A Statistical Analysis of Hitting Streaks in Baseball

Abstract

This article presents a study of hitting streaks for individual batters in the game of baseball. All baseball fans know that players go through periods where they never seem to make an out and other periods where nothing will get them to base. There is no doubt that “hot streaks” and “cold streaks” do occur. The question explored here is whether these streaks occur more (or less) frequently than would be predicted by a probabilistic model of randomness. I examined the records of many “regular” Major League players through four seasons, 1987–1990 and used several statistical methods to check for streakiness. These include standard methods such as the runs test, as well as a more complex logistic regression model with several explanatory variables. Based on all of these methods, there is no doubt that a certain number of players exhibited definite streakiness in certain years. But the evidence also suggests that the behavior of all players examined, taken as a whole, does not differ significantly from what would be expected under a model of randomness. Furthermore, none of the players examined in the study exhibited unusually streaky behavior over the entire four-year period.

Key Words:

• Logistic regression
• Runs tests
• Streaks