From SABR member Rob Mains at Baseball Prospectus on September 18, 2017:
I decided to determine how common walk-offs are in general, and what kind of walk-offs occur the most frequently. I mostly used the Baseball-Reference Event Finder. It tracks walk-offs only for plays in which the batter completes his plate appearance, so I used other sources for walk-off wild pitches, walk-off passed balls, walk-off errant pickoffs, walk-off stolen base attempts, etc.
I looked at walk-offs this season, as well as over the entire 30-team era beginning in 1998. Through Saturday’s games, there have been 192 walk-offs this year and 4,242 since 1998. That works out to a walk-off every 11.6 games this year and every 11.4 games since 1998.
Below you’ll see the frequency of walk-offs, starting with the most common in the 30-team era. Note that often a walk-off is the product of more than one event, like a single with a runner on first base, after which the outfielder airmails his throw to third base, allowing the runner to score. In cases like that, I considered the batter’s action to be the key, scoring plays like that as walk-off singles rather than walk-off errors. After all, the batter’s going to be the guy who gets water dumped on him.
Read the full article here: http://www.baseballprospectus.com/article.php?articleid=32792
Originally published: September 18, 2017. Last Updated: September 18, 2017.