Have the Yankees become more aggressive baserunners?

Baseball analysis is a tricky endeavor in April. The small sample sizes make piecing stories together difficult. Careful writers must sift through data and hazard guesses as to what’s meaningful and what’s just noise. At the same time, narratives emerge that paint incomplete pictures. They’re nearly impossible to shake once they set in, too. First impressions tend to stick, and that’s especially the case in baseball.

One of the more trendy observations currently in circulation deals with the Yankees and baserunning. There’s no shortage of reports indicating that the team has become more aggressive on the basepaths. A closer look, however, suggests otherwise.

Through 11 games in 2017, the Yankees have managed 12 stolen bases. The club also holds a BsR score of 0.9. For this all-encompassing baserunning measurement, 0 serves as league average. So far the story checks out. The Yankees currently stand out as an above-average team on the basepaths. They rank among the top teams in the majors in the pertinent baserunning categories.

The cracks begin to appear when you compare these numbers to the club’s 2016 campaign. The Yankees stole 13 bases through their first 11 games in 2016. That mark led the majors. This makes it impossible to say that the Yankees have increased their aggressiveness. If anything, it’s slightly decreased over the same time period from last season.

It gets even murkier when you look at the number of players with stolen bases. So far only three Yankees have swiped bags in 2017. Brett Gardner, Jacoby Ellsbury, and Chase Headley have each picked up multiple stolen bases in the early going. Over this same period last year, however, six different players registered stolen bases. In addition to the aforementioned trio, Didi Gregorius, Starlin Castro, and Alex Rodriguez picked up steals. Yes, even A-Rod.

That happened, and it was glorious.

If the team-wide baserunning numbers are down in 2017, how did this narrative get started? The answer comes in the form of the Yankees left field. Last season Gardner swiped just 16 bags. That was his lowest stolen base total over a full season in his entire major league career. It became a popular to criticize the speedster for staying anchored to first base.

This season, Gardner seems inclined to do everything in his power to shake that reputation. He stole five bases in the team’s first 11 games. He’s tied with Brian Dozier for the top spot in the American League. Compare this to last season, when Gardner stole just two bases in the club’s first 11 games. That’s a notable increase in aggressive baserunning and the narrative’s likely source.

According to Andrew Marchand, Joe Girardi gave both Gardner and Ellsbury a goal of scoring 100 runs this season. That could explain the uptick in stolen bases for Gardner. He might be motivated by his manager’s goal setting. Whatever the case may be, his increased activity is noticeable. The trouble is his individual baserunning is being projected across the entire team, which isn’t an entirely accurate representation.

The Yankees were quietly a very strong baserunning team in 2016. That fact somehow got lost in the season discussion. This year Gardner is off to a hot start on the basepaths. He’s been aggressive, but that doesn’t reflect the entire team. As the season unfolds, more data will become available and we’ll have a better picture of the club’s baserunning. For now, it’s best to leave the discussion centered on Gardner, and not the entire team.

Data courtesy of FanGraphs.