Throwing Heat: Is There a “Hot Hand” Among Baseball’s Top Pitchers?

Abstract

The hot hand, or the belief that “success breeds success”, has long fascinated sports players, fans, and statisticians. For 35 years, the debate over the existence of the hot hand has provoked research in baseball, basketball, soccer, golf, tennis, and more. However, despite a bulk of baseball hot hand research focusing on hitters, surprisingly little has been written about pitchers’ hot hands. We analyze at-bats for 50 MLB pitchers from the 2019 regular season using four statistical tests modified from earlier hot hand papers. Each address di↵erent common notions of streakiness. We find evidence against a Bernoulli model in 2 of these 4 tests. However, the tests appear to produce independent results, indicating that the hot hand may be more elusive than previously thought.