Something Aaron Miles Was the Best At, or Baserunning 2009

I wanted to find some baserunning statistics and was coming up empty (maybe I just don't know where to look) until I discovered that Baseball Prospectus has a section of their statistics site up for baserunning.  It should come as no surprise to people who've been to BP before that they use all sorts of odd sounding abbreviations like GA_OPPS, EqSBR, and EqOAR, but once you figure out what they all mean (through BP's stats glossary), it starts to take a clear shape.  (At least I think it does.  Hopefully some of the more statistically inclined here on BCB can come and confirm or correct what I'm trying to understand and explain here. Paging Shawn Goldman!)

The first thing to understand is the expected runs matrix BP works with.  For example, in 2004, a team with no outs and a man on second averaged 1.1596 runs.  A team with no outs and a man on third averaged 1.4535 runs, and a team with one out and the bases empty averaged .2866 runs.  So if Kosuke Fukudome leads off with a double, but then decides to try and steal third, he's taking a big risk.  If he succeeds, he could add a scant average of about .3 runs, but if he fails, he could take away a brutal average of about 1.2 runs.

So, if we added up all the extra expected runs a player's baserunning added and took away, we would have a way to value how many expected runs a player was worth on the bases.  To do this, BP tracks opportunities for advancement, split into various categories.  How many times did a player take the opportunity to advance from first to third on a hit?  How many times did a player take the opportunity to tag up on a fly ball?  Then, these tallied opportunities are compared to what the average ML runner did.  Then adjustments are made for park effects, etc.  What results is Equivelant Baserunning Runs or EqBRR.  

Last year,the league leaders in EqBRR were Michael Bourn with 15.0, Chase Utley with 8.8, Rajai Davis with 8.0, Dexter Fowler with 7.3, and Chris Getz with 6.2.  Melvin Mora, Jorge Posada, Carlos Lee, Billy Butler, and Yadier Molina were the five worst baserunners.

What about the Cubs?  Well, on the whole, the Cubs were a very neutral baserunning team.  [Edit:  See the comments below.  On the whole, the Cubs were a bad baserunning team, but what I originally intended still stands - that none of the individual Cubs were either very good or very bad.]  No one added more than 1.5 runs and no one took away more than 3.4 runs.  Milton Bradley and Kosuke Fukudome were the two worst baserunners this year.  Surprising no one, I'd expect, Aramis Ramirez, Jake Fox, and Geovany Soto were the next three worst.  What I think will be a surprise is that the next two worst baserunners were Alfonso Soriano and Ryan Theriot.  And the best baserunner?  Aaron Miles!  Sam Fuld was just behind Miles - not a surprise - but tied with Fuld was Koyie Hill!  #4 shouldn't surprise anyone - the professional Derrek Lee, but #5 is Big Z and #6 is Micah Hoffpauir!

Pardon all the exclamation points, but as I first dig into these, I am aghast.  When pitchers and bench players (especially a backup 1B and C) lead the team in baserunning, we are seeing that on the whole, the Cubs running game is mostly ineffective or counter-productive.  To be clear, it's not really bad - we shouldn't be wringing our hands here. 

But this does say something about the perceived baserunning value of Ryan Theriot and Alfonso Soriano.  2009 was no exception.  In 2008, Mark DeRosa led the team with 3.8 EqBRR, while Theriot and Soriano were both in negative figures again.  (Kouske was #2 that year, and there's hope that he might bounce back in 2010, especially if he stops stealing bases.)  In 2007, Pie, Izturis, and Marquis led the team, and while Theriot was positive that year, Soriano was negative again.  It is interesting that the players on the Cubs who have been good baserunners in '07 and '08 have been in the manager's doghouse and pushed off the team, but I'd caution against making too much of that.

Later today or tomorrow I'll post some ideas below about 2010 roster construction with baserunning in mind.  First, I'll be interested to read general reactions and confirmations or corrections on my understanding of BP's baserunning metrics.