Will the Blackhawks’ penalty kill remain a team strength next season?

SEATTLE — When the Blackhawks’ penalty kill was dominating opposing power plays earlier this season, players were quick to credit coach Jeff Blashill’s effective system for its success.

But Blashill, in turn, was quick to credit the Hawks’ excellent penalty-killers for its success.

That latter attribution seems accurate in retrospect, considering how substantially the unit has worsened since two of its three most important members — Connor Murphy and Jason Dickinson — were traded, leaving only Ilya Mikheyev behind.

The Hawks’ penalty kill somehow still ranks No. 1 in the NHL with an 83.6% kill rate, but since the March 6 trade deadline, they rank 27th at 73.8%. They’ve allowed a goal in nine of 15 games during that span, including the last four straight.

Some of those goals have been unlucky, such as Matt Savoie’s power-play tally Thursday for the Oilers, owners of the league’s best power play. It deflected in off Hawks defenseman Alex Vlasic’s skate in the crease.

But the stats mirror the results. Through March 5, the Hawks’ penalty kill had allowed the sixth-fewest shot attempts and ninth-fewest shots on goal per minute. Since then, they’ve allowed the 12th-most shot attempts and second-most shots on goal per minute.

Among the forwards, Dickinson’s departure forced Ryan Greene into a bigger role. Analytics show Greene has struggled, allowing the most shots and goals per minute among regular killers.

Among the defensemen, Murphy’s departure transferred more duties onto Louis Crevier, Artyom Levshunov (pre-injury) and now Ethan Del Mastro (post-Levshunov injury).

On Thursday, the Hawks did generate a breakaway and two-on-one rush shorthanded, but the Oilers’ power play nonetheless produced nine shots on goal.

Del Mastro allowed one seam pass through him that Murphy probably would’ve blocked. Crevier later got away with aggressively joining a rush, but he looked discombobulated upon returning to the defensive zone and ended up losing his position.

On Tuesday, the Jets’ power-play goal resulted from Landon Slaggert’s poor decision to pass backward on a rush, which Blashill dismissed as an individual error. But Blashill did examine more closely what allowed the Jets to generate two consecutive shot-tips.

Blashill has opted not to tweak the overall penalty-killing system, though, after evaluating what new weaknesses might be created by any adjustments to cover current weaknesses.

For clarification, the Hawks employ a variation on a “push-down” system with two defensemen stationed near the net while two forwards skate around and pressure the puck.

“Penalty kill is one of those things where there’s just so many different nuances,” Blashill said recently. “We certainly have our structure, but I don’t know any way to learn it without going through it. And so they’re getting those reps.”

Said Slaggert: “It comes down to execution and playing on our toes. When we force them to make plays under pressure, we have a lot of success. If we continue to do that, we’ll get right back to where we were.”

All of this raises a far more important question: Will the Hawks’ penalty kill remain a team strength next season?

If it doesn’t, the Hawks’ 26th-ranked power play will have to improve by an equivalent amount to pick up the slack.

One X-factor is whether Mikheyev, who has become one of the best killers in the league, re-signs or not. General manager Kyle Davidson has publicly stated his desire to do that, but no contract offer has been accepted yet.

Aside from Mikheyev, the personnel isn’t likely to change much over the summer, so these young killers will have to improve. The Hawks’ quest to find a new shutdown defensive center (essentially a Dickinson replacement) within their young forwards intertwines with this discussion.

Blashill’s system, which previously worked wonders with the Lightning, will be put to the test, too. Exactly how much of the credit does it deserve?