Jennifer Baldwin

 Changing the Rules
 A Chronology of Changes to Major League Baseball Official Rules

  by Jennifer Baldwin
  Senior Research Associate at the Cosmic Baseball Research Alliance

Alexander Cartwright and David Lucius "Doc" Adams, leaders of the New York Knickerbockers Base Ball Team drew up what is believed to be the first set of "official" baseball rules in the fall of 1845. The first game played with these so-called "Knickerbocker Rules" occurred on June 19, 1846. As this article's associated tables substantiates, there have been a variety of rules changes throughout baseball's organized history.

Many of those changes had to do with adjusting the balance between the pitcher and the batter. In 1893 when baseball moved the pitcher's mound back from 50 feet to 60 feet and six inches (60' 6") batting averages soared and strikeouts decreased. In 1963 when baseball expanded the strike zone batting averages dropped by 12 points, and homeruns declined 10 percent.

The tables in this report (use the links on the right) detail the changes by Rule Section and include several additional tables detailing rule changes for walks, batting averages and sacrifices. Table A lists all rules changes from 1845 through 1989.

Table ATable of All Rules Changes
Table 1Table of Rule 1 Changes (Objectives)
Table 2Table of Rule 2 Changes (Definitions)
Table 3Table of Rule 3 Changes (Game Preliminaries)
Table 4Table of Rule 4 Changes (Starting & Ending Games)
Table 5Table of Rule 5 Changes (Putting the Ball in Play)
Table 6Table of Rule 6 Changes (The Batter)
Table 7Table of Rule 7 Changes (The Runner)
Table 8Table of Rule 8 Changes (The Pitcher)
Table 9Table of Rule 9 Changes (The Umpire)
Table 10Table of Rule 10 Changes (The Official Scorer)
Table BTable of Rules Changes for Base on Balls (Walks)
Table CTable of Rules Changes for Sacrifices
Table DTable of Rules Changes for Batting Averages
Table ETable of Rules Changes 1845-1869
Table FTable of Rules Changes 1870-1899
Table GTable of Rules Changes 1900-1909
Table HTable of Rules Changes 1910-1919
Table ITable of Rules Changes 1920-1929
Table JTable of Rules Changes 1930-1939
Table KTable of Rules Changes 1940-1949
Table LTable of Rules Changes 1950-1959
Table MTable of Rules Changes 1960-1969
Table NTable of Rules Changes 1970-1979
Table OTable of Rules Changes 1980-1989

Major League Baseball Rule Book
In 1949 Major League Baseball re-codified the Official Rules of the game into ten sections:

  1. Objectives
  2. Definitions
  3. Game Preliminaries
  4. Starting & Ending Games
  5. Putting the Ball in Play
  6. The Batter
  7. The Runner
  8. The Pitcher
  9. The Umpire
  10. The Official Scorer

I would like to express my gratitude to my colleagues and staff at the Cosmic Baseball Research Alliance. Their helpful assistance was invaluable. --J.B.

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JCBA Vol. 20. Rule Changes
Published: December 15, 2001
Copyright © 2001 by the Cosmic Baseball Association