The Erik Karlsson-Marcus Pettersson pairing has been one of NHL’s best

The addition of Erik Karlsson to their blue line has been a total game-changer for the Pittsburgh Penguins this season.

Not only is he a massive upgrade over what they were getting from Jeff Petry in that spot, he is a future Hall of Famer that is one of the best players of his era and very clearly still capable of playing at an insanely high level.

We are starting to see that high level.

Karlsson has 11 points in his past six games and is back up to a better than point-per-game average for the season, taking over games and playing like an absolute force.

He is making the team, and everybody around him better.

That includes his defense partner Marcus Pettersson, as the two of them have teamed up to form one of the most productive defense pairings in the NHL this season.

The numbers are impressive.

There have been 65 defense pairings that have logged at least 100 minutes of 5-on-5 ice-time so far this season, and the Karlsson-Pettersson pairing consistently pops up near the top of pretty much every major category.

They have the league’s best goal-differential at 5-on-5, outscoring teams by a 16-4 margin in their 5-on-5 minutes.

They are also in the top-10 for shot attempt share (56.3 percent), expected goal share (59.9 percent), scoring chance share (61.4 percent), and high-danger scoring chance share (66.7 percent).

Basically, when they are on the ice the Penguins are controlling every aspect of the game and dominating on the scoreboard.

It has been everything the Penguins could have possibly wanted when they acquired Karlsson from the San Jose Sharks over the summer. And they seem to have found the perfect complement to him in Pettersson.

Anytime you have a player like Karlsson that excels offensively and has some shortcomings defensively, there is always an incentive to try and pair them with a more “stay-at-home” type defender to “cover” for them defensively. But as we saw so many times in the past with Kris Letang (Brooks Orpik, Rob Scuderi) that can only hold the pairing back because the “stay-at-home” guy can’t keep up. You need to find a player that has the defensive awareness, but also has the mobility and puck skills to not be an anchor on the other four players on the ice. Especially the defense partner.

With Letang, the Penguins found that player for years in Brian Dumoulin and I think they have found a pretty decent replacement — at least for now — in Ryan Graves.

They have definitely found that play for Karlsson in Pettersson, and it is bringing out the best in both players.

That has given the Penguins what should be considered one of the best top-four defensive groups in the entire NHL. On any given night they have one of Letang or Karlsson on the ice for 80-85 percent of the game. While the Letang-Graves pairing has not been quite as dominant as the Karlsson-Pettersson pairing, it has still been very good, very productive and on the positive side of every possible metric despite taking on a more defensive role. The Letang-Graves pairing is only getting about 46 percent of its zone starts in the offensive zone, but is still pushing the play in a positive direction, outscoring their opponents and tilting the ice (by comparison, the Letang-Dumoulin pairing a year ago was up over 52 percent in offensive zone starts).

There was always going to be some intrigue as to how the Penguins handled having Karlsson and Letang on the same roster, and it has been interesting to watch it all unfold.

Karlsson is getting turned loose offensively and given the top power play billing.

Letang is getting more defensive responsibility and taking on way more of a roll on the penalty kill.

The power play still has some inconsistency, but the penalty kill has been very good and the Penguins’ 5-on-5 metrics as a team have been among the best in the NHL.

You can see the pieces starting to come together, especially over the past couple of weeks.

Overall the Penguins have two great forward lines, one very promising forward line and two great defensive pairings. That is a strong foundation and the type of thing you can work with as a general manager in trying to fill the small holes that still exist to become a serious Stanley Cup contender. It is all, again, going to come down to health and goaltending. The rest of the team, though, is starting to come together. The addition of Karlsson, and finding the perfect defense partner for him, has been one of the biggest factors in that.