David Ortiz shifted his approach at the plate in 2009, perhaps hoping to generate more power on inside pitches. But instead, the results have been that he's not pulling the ball with power.

Over the winter, FanGraphs' pitch f/x guru Dave Allen studied Ortiz's struggles at the plate, focusing on Ortiz’s power and plate discipline. He concluded that Ortiz was swinging at pitches outside the strike zone and that it was a tendency developed over time -- dating back to the days of the prehistoric and lovably clutch "Big Papi" era. But that wasn't the surprising part. What shocked Allen was the type of pitches Ortiz swung more at in 2009: high pitches and inside pitches.

The above graphs are from the catcher's perspective. The contours are estimates of Ortiz's swing rate (and contact rate). So for a pitch at the solid line (50 percent contour), there is a 50 percent chance Ortiz will swing at it. Ortiz will swing at a pitch between the solid and dotted contour between 50 percent and 75 percent of the time. He will swing at pitches inside the dotted line more than 75 percent of the time. The graph shows that in 2009 he was more likely to swing at pitches up-and-in as compared to in 2007 and 2008. The next graph shows the same thing but for his contact rate -- the probability he makes contact with a pitch if he swings. The contour lines here are 80 percent (solid) and 90 percent (dotted). Since the area inside the 2009 contour lines is much smaller, there is a smaller area in which he made consistent contact compared to 2007 and 2008.

In his study, Allen surmised that perhaps Ortiz thought he would generate power only on inside pitches, so he forced the issue rather than taking these pitches as balls and waiting on better offerings.

But this shift in approach led to a drastic decrease in Ortiz’s power to right field. In short, he was sapped of any power when he pulled the ball. It also led to a decay in offensive production. In 2009, Ortiz posted a career low in home runs per fly ball, and he has yet to homer this season. So far in 2010, Ortiz has put only four balls into play that were not groundouts. Two went toward left field, one to center and one to right. This is counterintuitive to his aggressiveness on inside pitches.

Here's an illustration of his drop-off in pull power:

Interestingly, pitchers are feeding Ortiz fewer changeups and more breaking pitches (specifically curveballs) this season. It could suggest other teams think Ortiz’s bat control has diminished with his wrist injuries. In fact, his wrists could be so exaggeratedly slow that when he swings expecting a fastball, he makes contact with changeups. And, sadly, that might be an improvement over Ortiz’s typical 2010 result of a grounder or infield pop. Another discouraging sign for Papi this season is that he has missed on 44 percent of his swings, while the league average is 20 percent.

Is Ortiz done? It’s too early to say. On Monday, Ortiz took a ball to the warning track in center field and wound up with a double. It could be a spark -- or it could be an ember from a waning flame due to age and injury.

R.J. Anderson is a writer for FanGraphs. Images in this article are from Dave Allen's pieces on FanGraphs.