More than a third (35%) of the strikeouts by the Tigers staff belong to Justin Verlander (128) and Scherzer (121) Verlander and Scherzer are first and third in the league in punch outs with Mariners ace Felix Hernandez (122). The bullpen has also made a strong contribution as Joaquin Benoit, Brayan Villarreal and Octavio Dotel have each struck out more than 11 batters per nine innings.
While the Tigers strikeout record is impressive, the bigger story is the high strikeout rate across all of baseball. MLB pitchers have struck out an astonishing 7.5 per nine innings which is the highest K rate in baseball history by a fairly wide margin. The previous high was 7.1 in 2010 and 2011. If it keeps up that would mean an increase of more than 5% over any other season.
The figure below shows that this is not just a one year anomaly. Strikeouts have been on the rise for the past few decades jumping from 4.8 in 1980 to 7.5 this year, a startling 56% increase. As recent as 2003, the strikeout rate was just 6.4 per nine innings. So, we are seeing slightly more than one strikeout per game than we did ten years ago. That is a big difference.
Data Source: Baseball-Reference.com
What is the reason for the dramatic increase in strikeouts? There are are few possible explanations including:
- Pitchers are throwing harder than they did even a few years ago. It used to be rare for pitchers to throw 98, 99, 100+ MPH. Now, it seems like every relief staff has at least one pitcher who can do that.
- Over time, batters have been swinging for home runs rather than being content in making contact, although that probably wouldn't explain the more recent jump since 2003.
- Umpires could be playing a role too. It's possible that in an effort to speed up the game that MLB has encouraged umpires to increase their strike zones. This could also be occurring as a reaction to the performance-enhancing drug controversy.
- Offense usually dominates after expansion and then pitching tends to get better as we move further from expansion. There has been no expansion for 14 years, so you would expect pitching to be getting ahead of offense.