MLB Questions: Why Have Stolen Base Attempts Gone Down in 2013?

Here at Jockstrap Journal we think the stolen base is one of the more exciting plays in baseball. The pitcher winds and deals, the camera zooms out and we see a blur three-quarters of the way to second base. The runner sprints into a headfirst slide, his outstretched hand gracing the back corner of second base, before he’s gracefully tagged out. He stands up panting and smiling, focused on the new base 90 feet away… and then he realizes he’s out. It’s the uncertainty and the speed of play that make it exciting.

Unfortunately stolen bases are down in the first half of 2013 and we’re not sure why… And it’s not the Beard’s fault either…

Well, according to Michael Lewis of the novelistic masterpiece Moneyball, a potential basestealer needs to be successful 80% of the time in order for an attempt to be worth it. If a runner is thrown out, he can’t score and his team has one less out that inning to work with (duh!). That’s a double whammy of pain for getting caught*. But since the offensive climate in baseball has warmed up so much since Moneyball was researched and written, the success rate is closer to 67%-75% depending on who you ask. It’s possible that stolen bases are down because they’re simply “not worth attempting,” as runners are evidently not successful enough.

*If you’re into this kind of thing check out WPA graphs on Fangraphs and Run Expectancy Matrixes on Google. In fact, do it even if you’re not interested. Now!

Let’s look at the numbers. Teams averaged 70 stolen base attempts in the first half of 2013 compared to 78 SBA in the first half of 2012 (all per ESPN stats), 85 SBA in the first half of 2011, and 76 SBA in the first half of 2010. My first thought was that batters are getting on base less often and therefore have less opportunity to steal. And the average On Base Percentage in baseball during the first half of the 2013 season is .317, it was .319 in 2012, .319 in 2011, and .329 in 2010. So OBP IS down during the first half of 2013! That’s good news for my hypothesis, but not enough to prove a causal relationship between OBP and decline in SB attempts. That’s because OBP was constant from the first half of 2011 to the first half of 2012 and SB attempts were not. Plus, before the all-star break in 2010 when OBP was highest stolen base attempts were not. There’s apparently no link between OBP and SBA in this data.

My second thought – maybe base thieves have been less successful at stealing in the first half of 2013 and that’s why attempts are down. Let’s review the numbers. Catchers threw out 29% of base runners in the first half of 2013, 27% in 2012, 28% in 2011, and 28% in 2010.  Runners HAVE been less successful stealing bases in the first half of 2013! Even though the increase in caught-stealing is a marginal 1%, it’s worth investigating further to see how that number came to be. If catchers threw out a lot of baserunners early in 2013, it’s possible managers adjusted and that would explain the decreased attempts.

In April 2013, catchers threw out 27% of runners. They then threw out 29% in May 2013, 31% in June 2013 and 29% so far in July 2013. I was hoping the numbers in April would show an unusual number of caught runners to explain a decrease in attempts in May, June and July, but that is not the case. After looking at the stolen base numbers for April 2010- April 2012, it is worth noting that attempts were down in April 2013 from April 2010-2012. This means whatever the reason for the decrease in attempts was, it could have happened in the offseason.

Now I want to look at the top stealers from 2010-2012 to try and explain why stolen bases are down. If enough of them are stealing less, the aggregate could be a decline across baseball. The stolen base is uncommon enough where the leaders in stolen bases represent a disproportional number of total stolen base attempts. Think 2% of Americans control 98% of the wealth. The leaders (top 30) from 2010-2012 are (in order): Michael Bourn, Juan Pierre, Rajai Davis, Coco Crisp, Ichiro Suzuki, Jose Reyes, B.J. Upton, Drew Stubbs, Angel Pagan, Brett Gardner, Shane Victorino, Elvis Andrus, Emilio Bonifacio, Will Venable, Ryan Braun, Jimmy Rollins, Andrew McCutchen, Cameron Maybin, Ben Revere, Hanley Ramirez, Erick Aybar, Alcides Escobar, Carlos Gomez, Carl Crawford, Matt Kemp, Alex Rios, Carlos Gonzalez, Ian Kisnler, Ian Desmond and Austin Jackson.

Bingo! Bourn, Pierre, Davis, Reyes, Pagan, Victorino, Braun, Maybin, Revere, Hanley Ramirez, Aybar, Crawford, Kemp, Kinsler, and Austin Jackson have all missed time on the disabled list (15 out of 30 players). Of the healthy bunch only Andrew McCutchen, Carlos Gomez, Alex Rios, Carlos Gonzalez, and Ian Desmond have OBP’s above .314. That means only five of the top 30 base stealers are getting on base enough to be considered serious candidates for high SBAs.  The other 25 players have been injured or ineffective hitters and haven’t been stealing bases in line with their 2010-2012 averages. When the injured group plays, they’re not playing 100% healthy.

So, with nagging injuries, decreased game time, and simple ineptitude from such a large group of the top basestealers, it’s no wonder stolen base attempts are down!

You might raise the possibility that stolen base attempts are down because coaches, managers, and players want to avoid sliding injuries. Every season there’s a handful of players who get hurt because of headfirst slides and it’s possible that runners and coaches are being more cautious to avoid these injuries. But I don’t think this is it because injuries from sliding aren’t any more likely to happen now than they were in the past. Avoiding injury doesn’t explain the decline in stolen base attempts because players wanted to avoid injuries in 2010-2012 just as much as they do now in 2013. It’s a changing of the guard in the MLB, where the old base stealers are dying off faster than the new base stealers can replace them. Keep an eye out for Part 2 of this series where I’ll research the numbers and tell you EXACTLY how much of the decline in stolen base attempts comes from a decline in individual SBA performers.