Adam LaRoche’s Suddenly Elite Power

The Nationals’ plan to compete this year was a simple one: Trot out a rotation ballasted by Stephen Strasburg, Jordan Zimmermann and Gio Gonzalez, and hope somebody besides Ryan Zimmerman hits the ball.

There was little reason to believe that somebody would be Adam LaRoche. At 32, LaRoche was coming off a season of 45 awful games: 151 plate appearances of .172/.288/.258 hitting. A torn labrum sidelined him for the final four months of the season, and some sort of back injury was a yearly occurrence. His best season came six years ago when he was still with the Braves, a 32-homer affair with a 127 wRC+, his only campaign over 120.

In between lied an unremarkable career. LaRoche mustered wRC+ marks between 103 and 118 from 2007-2010, either just below or just above the first base average. He has a long swing, one that inevitably leads to a bunch of strikeouts (at least 20% of plate appearances every year except 2005).

But the length of this swing also lofts the ball and does so with great force:

When LaRoche launches his next home run, he’ll reach 30 for the first time since 2006. His .270/.343/.511 mark is quite similar to his 2007 performance, a .272/.345/.500 effort for the Pirates. But the average hitter put up a .264/.333/.416 line in 2007; the average first baseman is hitting .263/.337/.444 in 2012.

And so for the first time since 2006, LaRoche finds himself an impact player. But he isn’t doing anything new. He’s still a predominantly pull hitter with great natural power, a predilection to the fly ball, but mediocre contact skills. This skilllset wasn’t particularly difficult to find in 2007, when the league slugged .423 and its first basemen slugged .463. But five years later, many of those players that defined the league with their power have fallen away, either retiring or declining. LaRoche’s .511 slugging percentage ranks him fourth among qualified first basemen, behind Edwin Encarnacion, Albert Pujols and Prince Fielder. In 2007, the same mark would have ranked ninth, just behind the ever-capable Mike Jacobs.

LaRoche isn’t doing much he hasn’t ever done before. He’s taken steps above his career averages in most statistics this season, but not by much:

In a league where everybody has taken a step back, LaRoche has made himself into an impact player by doing just what he always has. All of a sudden, his power has gone from expected to excellent at first base, and the Nationals have capitalized on that power as a key component of their 2012 playoff run.