Resident Fantasy Genius: A Manager’s Impact on Steals

Major League Baseball clubs often pride themselves on being aggressive on the basepaths. While the scope of this article isn’t to examine whether this strategy helps win ballgames, we can say with absolute certainty that being aggressive on the bases is the favored approach among fantasy owners. Stolen bases can be difficult to come by, so finding unexpected sources of steals can make a big difference for a team looking to win a championship.

One way to come across such bargains is to look at players who are changing teams, going from one with a passive organizational philosophy to one with an aggressive philosophy. Lots of teams claim to be aggressive, but as with most things in this game, you can’t always take people at their word or reputation.

The most your fantasy competition likely does is read articles like these or look at the teams that attempt the most steals, but that can be very misleading. After all, raw stolen-base totals can be influenced by the personnel the manager has at hand. The most passive manager in the world will still lead the league in steals if he has Michael Bourn, Mike Trout, and Ben Revere patrolling his outfield and Jose Reyes and Jose Altuve manning the middle of his infield. No, if we’re going to be making decisions based on manager philosophies, we need to be more scientific than that. To that end, today I’m going to be examining which teams and managers are actually aggressive and which tend to be more prudent with their baserunners.

Methodology
For this study, I used the same methodology as I used the last time I looked at manager stolen-base attempt rates but with some improvements. Feel free to skip this section if you don’t care about the specifics.

My study uses a similar format as the With or Without You methodology Tom Tango made famous. I looked at all hitters who played under a particular manager in one season but under a different manager in either the previous or the following season. I then compared that player’s stolen-base attempt rate between the two years (while accounting for league average) to see how it changed when he was playing under a different manager. I then summed up all managers by year, with each hitter’s contribution to the manager’s bucket weighted by the lesser of his two stolen-base opportunities (with the manager and without the manager).

I ran some correlations to find the proper amount of regression and regressed each manager’s five-year total to come up with an initial estimation of his true talent level. After that, I started the process over again, but this time I used these initial estimates to adjust the “without manager” year. That is, a manager will get less credit for raising a player’s attempt rate if he played for a manager who didn’t like to run the year before. I ran several iterations of this process to come up with my final figures.

The numbers I present below include data from 2008 to 2012. The next step in this analysis would be figuring out how to weight these years properly, but that will have to wait for another day. For now, data from 2008 counts the same as 2012. I decided on five years unscientifically, mostly just as an attempt to get a large enough sample without going back too far, since manager tendencies and philosophies can change, especially in this day and age.

The Results
Below, you’ll find a table with every manager who called the shots in 2012 or will do so in 2013 (with the exceptions of Houston managers Brad Mills and Tony DeFrancesco. They both spent a significant portion of the season at the helm, and I didn’t have the data to break things up in partial-season chunks). For each manager, I’ve listed both the raw difference he would alter a player’s stolen-base attempt rate, what this number would look like as an index (which might be easier to conceptualize), and how many steals that would give (or take away) from a league-average player. So the league’s most aggressive manager, 2012 rookie Dale Sveum, would allow a league average SB-attempter (10.13 percent) to run 18.9 percent of the time—87 percent more than a typical manager would. Over 650 plate appearances (and assuming a league-average success rate), that would add nearly 10 steals to the player’s total.

Notes: Terry Francona and John Gibbons didn’t manage in 2012, but they do have previous experience. The numbers listed for them are their most recent five-year figures. Bo Porter has never managed before, but he served as a coach for the Nationals for the past two years. Washington manager Davey Johnson’s numbers are listed for him, as he may have picked up their philosophy as a coach. Walt Weiss and Mark Redmond are first-time managers and first-time coaches, so they haven’t learned under any other manager. They may follow organizational philosophy or do their own thing.

• One of the most interesting things about this list is the number of new managers who appear toward the top of the list. The 2012 rookies (and first-time managers), Sveum, Matheny, and Ventura, all like to let their guys run, as do 2011 rookies Roenicke and Farrell. Perhaps Weiss and Redmond will follow suit?

• It’s also interesting that despite reputations as “old-school” managers, guys like Baker, Manuel, and Showalter are all very prudent on the basepaths.

• Of the articles I linked in my preface, the Pirates, Blue Jays, Brewers, and White Sox all seem to mesh with their stated philosophies. The Rangers, however, do not. Ron Washington and first-base coach Gary Pettis may say they’re aggressive, and they may be ranked ninth in attempt rate since Washington took over, but their claims don’t hold up in this light.

• To satiate my curiosity, I ran a correlation on these results and with teams’ actual stolen-base attempt rates in 2012. Not exactly an apples-to-apples comparison, but it’s an interesting one since that’s likely the most your fantasy opponents will be taking into consideration. Correlation? 0.30. A relationship is there, as we’d expect, but it’s not particularly strong. Those raw leader boards can be very misleading.

• Red Sox players figure to receive a big boost this year, going from Valentine’s philosophy (0.95) to Farrell’s (1.59). Good news for Jacoby Ellsbury and Dustin Pedroia.

• Blue Jays players, meanwhile, stand to suffer as they move out from under the direction of Farrell (1.59) to Gibbons (0.99). Sorry Rajai Davis, Anthony Gose, Brett Lawrie, and Colby Rasmus.

• Colorado players like Carlos Gonzalez, Dexter Fowler, Troy Tulowitzki, and Josh Rutledge could also be in trouble with Jim Tracy (1.46) stepping down and Walt Weiss a complete unknown.

• Then there is the issue of the multitude of players changing teams this winter via free agency or trade. Over the next couple weeks, I’ll be catching up on all of these players individually based on this and other factors, so we’ll put them aside for the time being.

It’s unlikely any of the competition you’ll face in your leagues (or mine, for that matter) take this kind of thing into account in their draft preparations unless they read BP. That can give you a huge advantage as you prepare for the 2013 season, and we’ll help you out by incorporating this in our pre-season fantasy analysis.