Dead-ball era

In the history of Major League Baseball (MLB), the dead-ball era was a twenty-year period, roughly from 1900 to 1920, in which run scoring was low and home runs were exceedingly rare. In 1908, the major league batting average dropped to .239, and teams averaged just 3.4 runs per game, the lowest ever. Spacious ballparks limited hitting for power, and the ball itself was "dead" both by design and from overuse. Ball scuffing and adulteration by pitchers, particularly the spitball, were allowed, putting hitters at a disadvantage.

The era ended very suddenly; by 1921, offenses were scoring 40% more runs and hitting four times as many home runs as they had in 1918. There is no consensus among baseball historians as to why, but part of the reason lay in rule changes that promoted scoring, such as alterations of ballpark dimensions and the banning of certain pitches.