How sabermetric trends could affect the Cardinals: the stolen base

I get it. The stolen base isn’t the esoteric sabermetric statistic you were expecting to see at the end of the title. And now you don’t think you’ll have something especially intriguing to add to a conversation about the World Series in the next few days. But what if I told you the play that is one of the most exciting plays in the game of baseball, is slowly becoming obsolete.

It’s a good thing Dave Roberts, who completed the single most significant steal in baseball history, has a World Series game to prepare for because that will probably stop him from reading this article. Although the one-time Red Sock might be surprised, the prevalence of stolen base is declining.

The period that stretches from 2015 to 2017 saw the fewest stolen bases in any continuous three year period in the last 20 years. Here is a table of the production in each of the last 7 individual years.

As you can see, the number of stolen bases has dropped significantly from the 2011 regular season. It bottomed-out in 2015 and was not much higher during the 2017 season.

What happened? No one is entirely sure. There is speculation that more sabermetrically oriented teams have simply stopped trying to steal. They might be on to something—run expectancy tables show that this is a pretty good strategy. When a runner steals second base, the run expectancy increases by slightly more than 0.20, according to The Book. Furthermore, if a runner is thrown out trying to steal second base, the run expectance decreases by as much as .383.

In general, it is not worth it to attempt to steal a base. There are, of course, caveats to every rule. Say, for instance, your name is Billy Hamilton. Then, the above run expectancy values are likely skewed in your favor, but he is the outlier of all outliers in this scenario.

There is another notable factor to consider when looking for a reason why the stolen base has decreased. The first, is the concept of a “disruptive runner.” This type of player is one that will affect the defense. Again, from The Book, a batter will normally have a 12 to 16 point wOBA advantage with a non-disruptive runner on the bases. In other words, the disruptive runner has a negative affect on the batter, almost completely removing any affect he might have had on the defense.

In contrast, 5 of the top 10 teams in stolen bases this year made the playoffs. The Astros finished 8th, while the Dodgers came in 18th. There really does not seem to be a correlation one way or the other. This probably says more about an individual player’s ability to increase a team’s total number of stolen bases than it does about an overarching strategy that definitively leads to success.

For instance, the Angels, Brewers, and Reds finished in the top 3. The Angels had Cameron Maybin and Mike Trout. The Brewers had Jonathan Villar and Keon Broxton. And the Reds, of course, had Billy Hamilton, who stole 59 bases—more than 4 teams. None of these teams made the playoffs.

While speedy players are certainly exciting and might appear to affect the outcome of a game—this is most visible when a pinch-runner enters in a tied or one-run game—it does not appear that stealing bases alone is a strategy that will significantly increase wins over the course of a 162 game season.

The benefits that come from speed cannot be limited to the stolen base. There are more nuanced ways to improve run expectancies with your feet such as going first to third or advancing on a ball in the dirt.

With these things said, it is clear that the Cardinals do not need to go out and chase (haha) a speedster in free agency. What they should focus on and what would be more productive, is instructing the players they do have how to advance on the bases.