in the 1880s the number of balls required for a walk was gradually reduced from 9 to 4 and a strikeout changed from 4 strikes to 3. At the time, foul balls were not counted as strikes.
Source: Hample, Zack. Watching Baseball Smarter: A Professional Fan's Guide for Beginners, Semi-experts, and Deeply Serious Geeks. Knopf Doubleday Publishing Group. Kindle Edition. p129
In the 1960s pitchers dominated baseball. Most fans admired pitchers, but they loved hitters. When their heroes failed, game after game, to produce the excitement they craved, growing numbers stopped going to the ball parks and wouldn’t even turn on the television to watch a game.
In 1969 the rules were changed, shrinking the strike zone to narrow the pitcher’s target and lowering the mound from 15 to 10 inches to flatten their curves an mitigate their speed. Batting averages, home runs, and attendance all began to climb satisfactorily again.
Source: Geoffrey C. Ward and Ken Burns, Baseball, an Illustrated History (New York: Alfred A. Knoff, 1994) p 401
