By any objective measure, the Ottawa Senators aren’t a very good hockey team. They would technically make it into the playoffs as the second wild card seed if the season ended today, but that says a lot more about the state of the East’s middle class than it does about anything they’ve done to distinguish themselves. The positive goal differential they’ve managed to maintain at even strength has been propped up by some favourable percentages at both ends of the ice, masking the fact that they’ve been the second-worst possession team in the league.

Yet somehow, it’s easy to imagine those good fortunes continuing to move forward, if only because of the raw talent at the top end of the roster. Mike Hoffman is establishing himself as one of the NHL’s most lethal goal scorers, and Craig Anderson has somewhat quietly been one of the more reliable goaltenders during his time in Ottawa.

There’s other nice pieces kicking around there, too, but there’s no question that every single shred of success for the Senators runs entirely through Erik Karlsson. That much is evident when you break down the splits for the team with him on the ice versus while he’s on the bench during five-on-five play:

	Shot Attempt Differential	Scoring Chance Differential
With Erik Karlsson	15	-6
Without Erik Karlsson	-258	-123

His individual differentials here aren’t necessarily all that impressive in a vacuum, but it’s telling that they’re at least keeping their head above water while he’s on the ice, while being absolutely caved-in during every other situation. All of the other numbers are equally staggering.

He has 13 more points on the season than all six other Senators defensemen that have dressed combined. He’s currently 4th in the league in scoring, sitting right between the likes of Tyler Seguin and Vladimir Tarasenko. His current 82-game pace of 89 points would be the 26th most-ever by a defenseman, with only Nicklas Lidstrom’s 80 points in 80 games in 2005 being the only time a blueliner has reached that plateau this century.

His name has deservedly been gaining some traction in the discussion of Hart Trophy candidates. While defensemen generally haven’t been recognized as such in the past – heck, Chris Pronger is the only one to have won it since the early 1970’s – the year Karlsson is cobbling together has merited that discussion purely based on the sheer load he’s carrying for his team.

In a macro sense, his success is helping put into question many of the ideals about what constitutes good defense. Qualitatively, it’s easy to see how his galavanting style of play could rub purists the wrong way. After all, the NHL has a habit of coaching all of the fun and creativity out of people over time in favour of a more conservative approach. When he makes a mistake, it tends to be of the glaring variety. It’s human to struggle with ridding the lasting images of those gaffes from the mind. The fact that he also doesn’t kill penalties only adds fuel to the fire for his skeptics.

All of those epithets go directly against all of the conventions that have been drilled into the minds of hockey fans since Day 1 for what a prototypical defenseman is supposed to look like. The game has evolved since then, and in turn the position itself has received a facelift accordingly. The following point is the one which honestly can’t be emphasized enough: a good offense is the most effective and sustainable form of defense.

The reality is that it’s exceedingly difficult to actually defend on a consistent basis in your own zone at the NHL level. The players are too skilled, and the way the game is officiated isn’t nearly as forgiving as it once was. If you’re living in the defensive zone, you’re essentially spinning a wheel with three possible outcomes:

a) Taking a penalty and going down a man for two minutes or less

b) Tiring yourself out to the point where you’re suppressing your own offense

c) Conceding a goal against

All of which makes puck possession all the more important. Beyond just the possibility of generating a goal of your own, as long as you have control of the puck the likelihood of the opposition scoring one going the other way plummets. That’s not even ‘advanced’ or ‘analytical’ per se, as much as it’s an intuitive line of thinking.

For the most part, teams seem to be catching onto this. What used to be a position crowded with slow, lumbering, ‘stay-at-home’ types, is now being refurbished with players whose best assets are their smooth skating and slick passing. There have obviously been players in the past who were ahead of their time sprinkled around the league, but it’s much more commonplace these days.

Erik Karlsson is the current zenith of that, spearheading the evolution. Much of the talk about how he’s a liability in his own zone seems to be rooted in the aforementioned nebulous idea that there’s only the one way to be effective as a defender. Whatever the case is, it’s certainly not based in reality.

That point can be illustrated by a relatively inconspicuous play during a recent game against the Tampa Bay Lightning.

After an initial lapse during which the oncoming attacker made a nifty move to cut into the zone with possession of the puck, Karlsson makes a play that very few other players would even have the physical capability of attempting.

He not only catches Vladislav Namestnikov, cutting off his angle to the net, but actually displaces the puck from his stick with an expertly timed poke-check. It winds up harmlessly careening to the corner, at which point reinforcements help win a battle along the boards and get it out of the zone within a matter of seconds.

Just like that, he defused a situation which could have, and almost certainly would have resulted in a high quality scoring chance against had a less adept defender been involved. There’s something poetic about him making such a subtly effective play in his own zone while TSN flashes a graphic about his fellow teammate’s hitting proficiency.

This is something I made a note of while tracking a Senators game earlier in the season. There’s no question that the most devastating skill in Karlsson’s repertoire is his ability to transition the puck out of his own zone with speed and precision, quarterbacking the offensive attack.

What gets overlooked is his innate ability to protect his blueline by utilizing that same speed and spatial awareness. His skating allows him to be more aggressive knowing full well that he has enough recovery speed to erase a mistake should it arise. If you’re an opposing forward, this forces your hand. Since it’s doubtful that you’ll beat him out wide, chances are that dumping the puck in is the path of least resistance. All of which is, in theory, exactly what he wants you to do, because his chances of snuffing out the attack entirely by going back and retrieving the puck himself are greater than they are for most.

You can see the bind this method of defending puts a prospective forward from the other team in. It most certainly isn’t as cushy a proposition as looking up and seeing Jared Cowen standing there, willingly ushering you into the zone as he sags back until he’s effectively run out of real estate and it’s too late.

These are important distinctions to make. Despite all of his eye-popping numbers and offensive accomplishments, the notion that a player of Erik Karlsson’s ilk can be an effective defender is still greeted with skepticism in certain quadrants of the hockey universe. He is, even if it’s accomplished in a different form than we’ve become accustomed to seeing from prototypical building block defensemen of eras past.

In today’s game, he’s hardly a singular talent in that regard. There’s a plethora of other great, wildly effective defensemen spread all across the league. Whether it’s a Doughty, or Subban, or Keith, or Klingberg, there’s no question that we’re in a golden age of defensemen.

All of those guys make this a great time to be a hockey fan. Karlsson just so happens to be doing it at a higher functionality than the rest of them are right now.