Someone recently mentioned to me that strikeouts in the major leagues were at an all time high.  So I did what anyone would naturally do: Write some R code to scrape baseball-reference.com, collect team data for every team over the past 112 years, and plot it.  The results are below:

Things to notice:

• The strikeout rate for the first 15 years of the 20th century was relatively flat at around 10%.
• There have been two major drops in strikeout rates.  The first was from about 1915 through 1920, the second was between the late 1970s through 1980.
• The first drop in strikeout rates was around the beginning of Babe Ruth’s when power hitting became a more prominent part of the game.
• The second major drop followed a rules change where the mound was lowered from 15 inches to 10 inches for the 1969 season.
• These two small periods of rapid decline were both followed by long stretches of slowly increasing strikeout rates.  Strikeout rates steadily climbed from about 1920 through the mid-1960s, and then again from 1980 to present.
• In 1973 the American League introduced the designated hitter (DH).  Before 1973, the American and National leagues had very similar strikeout rates.  After 1973, one can see a clear separation of the leagues as the National league, not surprisingly, has had a higher strikeout rate than the American league every year since the beginning of the DH era.
• The team with the highest strikeout rate in the last 112 years was the 2010 Arizona Diamondback who finished 65-97 with a strikeout rate of nearly 25%.  Before 1980, the team with the highest strikeout rate was the 1968 New York Mets.
• The team with the lowest strikeout rate of the last 20 years was the 2002 Anaheim Angels who won the World Series that year.  Since the mound was lowered, the 1980 Texas Rangers have the distinction of having the lowest strikeout rate for a season.  The lowest strikeout rate for any team since 1901 was the 1901 Boston Americans with a strike out rate just over 5%

Cheers.