Hitting Streaks Don't Obey Your Rules: Evidence That Hitting Streaks Aren't Just By-Products of Random Variations

TL;DR

This study shows that hitting streaks in Major League Baseball occur more frequently than random chance would suggest, indicating factors beyond simple randomness influence streak formation.

Contribution

The paper provides empirical evidence that real-life hitting streaks exceed expectations from random permutations, challenging the assumption that streaks are purely due to chance.

Findings

Real-life streaks are significantly more numerous than in randomized data.

Removing non-starts increases streak counts in permutations but still below real-life levels.

Results suggest possible psychological or strategic factors influencing streaks.

Abstract

There have been more hitting streaks in Major League Baseball than we would expect. All batting lines of MLB hitters from 1957-2006 were randomly permuted 10,000 times and the number of hitting streaks of each length from 2 to 100 was measured. The average count of each length streak was then compared to the corresponding total from real-life, when the games were in chronological order. The number of streaks in real-life was significantly higher than over the random permutations. Non-starts (such as pinch-hitting appearances) were removed since these may be unduly reducing the number of streaks in the permutations; the number of streaks in the permutations increased but was still significantly lower than real-life totals. Possible explanations are given for why more streaks have appeared in real-life than we would expect, including possibly the hot hand idea. Contact at trentm@email.unc.edu