Baserunning: Was it Really a Problem Last Year?

This offseason, Gardy and the Twins coaching staff have repeatedly been quoted, citing the need for the Twins to become more "athletic" and run the bases better. With the 2011 season only a few short days away, and with Alexi Casilla and Tsuyoshi Nishioka replacing J.J. Hardy and Orlando Hudson in the middle infield, it appears the Twins have at least partially made good on their promise.

But was base running really a problem for the Twins in 2010? At first glance, according to the most well known base running statistics, stolen bases and caught stealing, the Twins have dropped off considerably over the past two years.

Stolen bases, total attempts (including pickoffs), and success rate have each dropped from year to year. So I understand the viewpoint. But before I agree with the team, after the jump I'm going to take a bit deeper look at the Twins base running in total over the past three years.

A couple of years ago, I wrote a series of articles focused on "Total Run Accounting", aiming to break down all aspects of baseball into the runs created (or negated) by each player on each play. In this article, I focused on base running in quite a bit of detail. I won't repeat the full explanation of my process today, but the basic idea is to break down each play into a set of "subplays" where expected runs (the number of runs an average MLB team can "expect" to score based on number of outs and runners on base) can be allocated (positive or negative) to a specific batter, base runner, fielder or pitcher. For the purposes of this analysis, I break down base running into stolen bases, including caught stealing) and "extra bases" (going from first to third on a single, advancing on a fly ball out, etc), including making outs on the base paths.

First, let's look at the stolen bases from an "expected runs" standpoint, adding a few columns to the table above. In the table below, "ER_SB" means expected runs due to successful stolen bases, "ER_CS" means expected runs lost due to times caught stealing (and pickoffs), "ER_ALLSB" is the sum of ER_SB and ER_CS, and "RAA_ALLSB" is the total number of runs created (or prevented) relative to MLB average for the given season.

Immediately, we see that even though the total number of steals and success rate went down from year to year, the Twins performance creating runs relative to league average actually improved slightly each year. Why is this? As I noted a couple years ago, stealing bases is generally a losing proposition for teams when we look at expected runs. This is because the number of expected runs lost due to being caught stealing is much greater than the amount gained by a successful stolen base. For example, with a runner on first and no one out (Expected Runs ER = 0.94), a successful steal of second base results in a +0.25 run improvement (ER = 1.19). But an unsuccessful attempt results in 0.66 runs prevented, emptying the bases with one out (ER = 0.28). This means that a team must be successful 71.9% of the time in order to break even in this situation. With one out, the "break even" success rate increases to 78.9%, with other situations falling in between. Since the MLB average stolen base success rate has remained a relatively constant 72-73% over the past three years, not to mention pickoffs being included in the equation, the average MLB team lost 6.9 runs last year solely due to stealing bases.

In the Twins case, fewer stolen base attempts, as well as fewer times caught stealing, means fewer expected runs lost on the base paths. But this does not tell the whole story. Comparing 2009 to 2010, the Twins stole 17 fewer bases, yet the total expected runs gained from stolen bases only decreased 0.1 runs. This is because the stolen base "reward" depends on the situation. As noted above, a successful steal with a runner on first and zero out means +0.25 expected runs. The reward drops be nearly half, to +0.13 with one out, and by nearly half again to +0.07 with two outs. So while I haven't broken down the numbers, I suspect that a larger percentage of the Twins successful stolen base attempts were in the "high reward" zero out situation last year.

Second, let's look at the runs created or prevented due to taking extra bases on batted balls, as well as staying put (not attempting to go from first to third on a single, for example) and getting thrown out. In the table below, "EB" means total extra bases, "EB_Added" means total number of extra bases added above what would be expected from a league average base runner, and "RAA_BATTED" is the total number of expected runs above average due to extra bases, staying put and getting thrown out after batted balls.

We see that the Twins had an amazing base running year in 2008, taking a league high number of extra bases and creating the most runs on the base paths in the American League. In 2009, the Twins actually performed better relative to league average, taking fewer extra bases and getting thrown out less often. But that season saw the Angels (+31), A's (+23) and Rays (+17) all creating more runs than the Twins. In 2010, the Twins base running dipped nearly ten runs relative to league average, mostly due to an additional 7 runs lost compared to 2009 due to outs on the base paths. Watching last season, it appears likely that much of this decrease (with same number of outs) is due to making so many outs at home, due to sending Jason Kubel to be thrown out by 30 feet so often.

Overall, when we consider all aspects of base running, including both stolen bases and extra bases, we confirm that the Twins overall base running performance decreased by nearly 10 runs relative to league average in 2010. But we also see that despite the dropoff, the Twins remained firmly in the middle of the AL pack.

What can we conclude from all of this? First, and not surprisingly, the Twins appear to have cost themselves around 7 to 10 runs last season compared to 2008 and 2009. So base running appears to be an area for improvement. But I would caution against sacrificing other strengths including hitting and fielding in order to improve base running. While Alexi Casilla and Tsuyoshi Nishioka may be worth an extra 10 runs on the base paths compared to J.J. Hardy and Orlando Hudson, it is entirely possible that they may give up at least that many runs with their gloves, not to mention their bats. Every move is ultimately a tradeoff, but I understand cost is also a very important factor. We will see whether the Twins base running is improved in 2011, hopefully Casilla and Nishi will produce at the plate and on the field while improving on the base paths. Can't wait until the season!