Measuring Defensive Assignments on the PK

We know that the ratio of offensive-to-defensive zone faceoffs is a big driver of a player's results at even-strength.  On the PK?  Not so much - almost all faceoffs taken by a shorthanded team are in their own end.  But, as we've discussed before, there are usage differences on the penalty-kill too - in particular, some players get sent out for faceoffs (and thus start in their own zone all the time) while others go over the boards once the puck has been cleared, which puts them in a situations that are not quite as dangerous, on average. 

The quantity we want to look at is "Defensive Zone Starts per 60 minutes".  Here are the 2009-10 leaders:

As it turns out, centers are most likely to be used in this way, and the impact on their stats is undeniable:

Many PKs use two centers today, in case one gets kicked out.  So the wingers who lead in zone starts are a truly-gifted defensive crew:

A couple of these guys are still part-time centers (maybe 5% of the time), so it's a judgment call on what they're doing on the ice on a PK draw.  As for defensemen:

That's mostly a crew of tough defensive defensemen - of course, usage here depends on a coach's strategy, and on how many solid defensemen a team has.  It's a surprise to see O'Donnell here on a team that has both Scuderi and Doughty, but I'd imagine it happened because those two were on the ice so much they weren't necessarily available to immediately kill a penalty.