Defense up the middle and power at the corners -- it's the classic method of sorting players into various positions based on their physical abilities that has held true for most of baseball's history. The four up-the-middle positions on the field have long been defense-over-offense positions, with teams focusing more on run prevention than run creation in those spots. Naturally, that put more pressure on the corner positions to produce the bulk of the offense, so with athletes and defenders up the middle, baseball has generally filled out those four spots -- first base, third base, left and right field -- with guys who hit first and figure out how to play defense later.
That's how it used to work. But like so many other things in baseball these days, the type of players teams are sorting into the various positions are also changing, and nowhere is this more obvious than in the dramatically changing profile of the modern left fielder.
Before we get to the data, let's just try a fun little quiz: Name three current major league left fielders who you would describe as offensively gifted but defensively challenged, the kind of guy who would have fit in with Manny Ramirez or Albert Belle, or Jim Rice even further back. With 30 starting left fielders, it shouldn't be that hard to find three bat-first sluggers, right?