Mains: The stop sign at second base

From SABR member Rob Mains at Baseball Prospectus on January 8, 2018:

When I wrote about some under-the-radar trends in the 2017 season, I missed one: Triples. Triples are way down during 21st century baseball in general, and the current decade in particular. (Throughout this article, I’m going to look at the divisional play era, 1969 to the present.)

By this measure, the five seasons in baseball history with the fewest triples are, in order: 2013, 2017, 2014, 2010, and 2016. We’re in a triples drought.

This struck me as curious. This isn’t just a reaction to the scoring environment.


It makes sense that, in a high-scoring environment, there’s less reason to stretch a double to a triple, because the batter behind you has a good chance of driving you in whether you’re at second base or third base. Statistically, that means the correlation between triples and scoring would be strongly negative: More scoring results in fewer triples. But that’s not what’s going on here. The correlation between triples and runs per game is -0.30. It’s negative, but barely. It’s not a strong relationship.

This got me thinking: How widespread is the aversion to advancing from second base to third base?

Read the full article here:

Originally published: January 8, 2018. Last Updated: January 8, 2018.