There’s a lot of interest in [Andy] Sutton as a big-time rental. For a team like Washington, Sutton could help them beat Pittsburgh and get to the Cup Final. For an impact defenseman, you make the deal and don’t look back." - An anonymous NHL director of pro scouting
The Washington Capitals are apparently one of eight teams interested in acquiring Islanders UFA-to-be defenseman Andy Sutton, and, on the surface at least, such interest seems to make sense. Sutton's big (listed at 6-6, 245), tough, and more than a little bit dirty. He blocks shots, doles out hits by the bushel and has more than 500 games of NHL experience. He is, it would appear, the embodiment of everything that fans pine for in "a crease-clearing defenseman."
But how big an upgrade is Sutton over what the Caps already have? For the sake of comparison, let's take a look at the nearly 35-year-old blueliner next to the Caps' closest approximation of the proverbial crease-clearer, John Erskine:
The numbers to focus on here are the overall and shorthanded ice time, hits and blocked shots (the plus-minus differential is obviously huge, but given the teams on which the two rearguards play, not terribly significant). Sutton plays more and tougher minutes than Erskine, but that disparity in hits (a dubious stat which may be significantly over-counted on the Island to begin with) disappears when you look at it as a per-minute rate. The blocked shot differential is huge, but no doubt aided by Sutton's 85 extra minutes of penalty killing time, as those are prime shot-blocking minutes. Still, there's no denying that Sutton is an elite shot blocker.
Going beyond these "traditional" stats, we can look at Goals Versus Threshold (or "GVT") to approximate "the value of a player, in goals, above what a replacement player would have contributed." In terms of offensive contribution, Sutton is far and away the more valuable player, with a 1.0 to -0.6 advantage in Offensive GVT over Erskine - that is to say that Sutton is a little bit better offensively than a replacement defenseman would be, and Erskine's worse offensively than that imaginary rearguard snatched up off the scrap heap.
On defense, however, it's a different story - both Sutton and Erskine have a 1.7 Defensive GVT (which isn't a terribly impressive number to begin with and ranks fourth among blueliners on both the Isles and the Caps). Of course, those 1.7's aren't created equal, as Sutton's have come in those harder minutes. Further to that point, here is what each of our subjects has been able to do at five-on-five this season:
As noted earlier, Sutton plays tougher minutes than Erskine (as evidenced by the high QualComp), but the interesting number here is the GAON/60. Sutton's 2.40 comes while playing big minutes for a team with a 2.7 GA/60 at five-on-five, meaning that when he's off the ice, the team is much worse off defensively. Similarly, Erskine's 1.81 for a team whose GA/60 is 2.2 is impressive (but in far easier minutes).
Down a man, Sutton has an 8.53 GAON/60 while playing for a team that has a 9.1 GA/60 at four-on-five, so he's better than his teammates... but not impressive. Erskine's 9.95 mark, however, for a team with a 7.3 GA/60 at four-on-five, is downright woeful.
Andy Sutton is an upgrade over John Erskine, there's no doubt about that. But when you look at just how big an upgrade he might be (is he a second-pairing defenseman for a contender and, if so, can he truly handle that role?) - and throw in the fact that Sutton has all of four games of playoff experience in his career - it gets harder and harder to justify giving up a lot for Sutton. It certainly isn't a situation in which you "make the deal and don’t look back"... is it?