Writing for ESPN Insider, Dayn Perry of FanGraphs asks the question many among us have asked: What happened to Jason Heyward? (Link requires registration.) Using the best data known to man and computers, Perry offers this telling snapshot:

Heyward is trending in the wrong direction when it comes to line-drive percentage (17.8 percent in 2010 to 13.9 percent in 2011), infield pop-ups (8.4 percent to 24.7 percent) and batting average on balls in play (.335 to .245). In the case of his declining BABIP, there's almost certainly some bad luck involved, but the remaining indicators are more troubling.

Additionally, he's swinging at 44.8 percent of pitches overall, up from 39.4 percent last year; and he's swinging at 28.7 percent out of the zone after hacking at just 24.2 percent of such offerings. Add it all up and you have a guy who's hitting fewer line drives and more pop-ups and seems to have lost control of the strike zone.

We've noted before that Heyward is swinging more and accomplishing less. (His batting average and on-base percentage tell us that much.) We've also noted that this is the truly baffling part. Unlike, say, Jordan Schafer, who has struck out a lot at every level, Heyward arrived in the majors bearing the stamp of a young player who knew the strike zone and could work a count.