Who knows why Josh Willingham left first base with the intention of stealing second base on April 27th, 2013.
Coaches claim the thievery was not planned. Itís possible that with the left-handed Michael Kirkman on the mound, Willingham was fooled by his delivery or was caught leaning when the Ranger threw over to first. Either way, with his team up 4-0 -- thanks in part to his two-run home run two innings prior -- Willingham broke for second, took the base but aggravated his knee in the process. All for what?
The knee, which he had injured in 2010 while with the Nationals, gave Willingham troubles the rest of last year. For the remainder of the season, the man who had punished pitching and made people think the concrete had finally settled at Target Field in 2012 hit a Punto-nian .200/.332/.336 over nearly 400 plate appearances.
With the left knee out of commission -- the right-handed sluggerís front knee which absorbs the impact in his stride and weight transfer and twists violently when he is opening up his hips to turn on the ball -- Willinghamís power drained significantly. He hit just 14 home runs compared to the 35 he had in 2012. His standard fly ball distance dropped from 279 feet to 265 feet on average.
Whether or not directly related to the knee injury, what gave Willingham the most trouble was doing anything with pitches on the outer-half of the strike zone.
In 2012 he hit .217/.337/.422 with 22 extra base hits including 11 home runs on pitches on the outer-third of the plate. This past year he managed to produce just a .170/.296/.224 batting line that included nine extra base hits (all doubles). The heat maps and spray charts from ESPNís Stats & Info Department show how much better Willingham was at hitting those pitches for power and driving the ball for distance. In 2012 his average fly ball distance on those pitches was 296 feet. Last year the average distance dropped to 255 feet.
Based on the heat map of his slugging percentage (left) it is clear Willingham thrived when being able to extend his hands on pitches up and out over the plate to drive the ball. In 2013, he was unable to get the desired results on the same pitches as he did in 2012. Interestingly enough, his contact rates in that location in these two seasons are very comparable but the production simply dropped off.
It is indeed likely the knee was the catalyst for the plate coverage power drop-off, when we see that in both 2011 and 2009 he hit six home runs on the outer-half of the plate but in 2010, when he injured his knee and required surgery on his meniscus, he had just one home run and very little power (.277 slugging).
The takeaway is that once healthy in 2011, Willinghamís power rebounded nicely (29 home runs, .477 slugging percentage overall). If healthy in 2014, the Twins should expect the home run power to return.
All graphs and data provided by ESPN Stats & Info.