September 3, 2013
Painting the Black
For Detroit, Who'll Stop the Run?
How flawed is too flawed?
Detroit entered the holiday weekend with the American League's largest division lead and exited, thanks to a series win against second-place Cleveland, all but assured a spot in the postseason. As a result the Tigers now inhibit that special late-season territory, where we no longer worry about how a team will make it to October, and instead wonder what they'll do when they get there. Most arrive at these conclusions through some means of micro-analysis. To wit, Jon Morosi of FOX Sports raised a valid concern last week about the Tigers: their catchers' AL-worst caught stealing rate.
Armed with that information and nothing more, it stands to reason the steal-happy Rangers and Red Sox could give the Tigers fits; so could other teams' designated pinch-runners. Yielding free bases is never a good idea, and even if the differences between the regular season and postseason run-scoring environments are historically overstated, the differences in exposure are not. A battery can give away second base late in a July game without anyone hooting, but not so in October. Still, while Morosi's point is valid, there is another side to it: caught stealing rates, as a stat, tell lies.
Let's state the obvious: caught stealing rate is true to its name. The metric measures what it claims to, whether the basestealer succeeded or not, on a per attempt basis, and does so about as well as a stat concerned with a binary conclusion can. The trouble is with the application. In a sense, caught stealing rate is a defensive-minded cousin of runs batted in: both tell us an ending without giving us the rest of the story. For an example, let's get back to the Tigers and their pitiful caught stealing rate:
Tigers Pitchers by CS%, 2013 (Min. 5 SBA)
There is no staff-wide incompetence here, just a few pitchers dragging the group down; not surprising, since caught stealing doesn't weigh the best possible result (i.e. no attempt whatsoever). Without Verlander, Sanchez, and Benoit's negative contributions, the Tigers would rank second in the AL in caught stealing rate. These other pitches aren't the only ones with sullied reputations, however.
Each time we use caught stealing rate to judge a catcher we partake in cognitive dissonance. A few weeks ago, I detailed how the best right-handed pitchers shut down running games. Nobody objected to the idea that pitchers are more responsible for controlling the basepaths than catchers. But we all—myself included—continue to use caught stealing rate to determine how good a catcher is at throwing.
Alex Avila's last few stolen bases against provide a clear example of how this approach misleads. Although Avila's throws were not perfect in location—some were offline, one bounced—he popped at good times, and may have nabbed a runner or two were it not for large leads gifted to them by the pitchers. Granted, Avila deserves some blame, for the throws' geography as well as not using the tricks in his bag, like the snap throw, to help his pitchers out. But Avila's caught stealing rate is more likely to become an issue than Verlander's because hardly anybody looks at caught stealing rate for pitchers.
If one were to build a caught stealing metric that is fair to catchers, then what information would it comprise? In an ideal world you could cobble together pitch location and type, the pitcher's time-to-home, the catcher's pop time, and the catcher's throw location, then model expected caught stealing rate based on those variables. Since man hours are an issue, using the two times would have to do. There's just one problem: that information isn't publicly available for every stolen base. Some data providers are tracking these times already, and others plan to expand to the minors in due time. What information is in the public realm is bare bones.
This is where we must face reality. Teams, through these means and additional scouting information, will hold the advantage in evaluating the running game on a macro basis. Unless something changes in the near future, the public's go-to metric will remain caught stealing rate, despite its obvious shortcomings. The only hope here is smarter evaluation of the running game on a micro basis—even if it means watching the Tigers this postseason with a stopwatch in hand.