Brian Dumoulin is not an offensive defenseman. The reliable, 26-year-old blueliner averages about 15 points a season and has six goals in his NHL career – four of them this year.

Saturday night in Toronto, though, he scored a beauty.

With the Maple Leafs up 3-0 late in the second period, Dumoulin made a power move to cut across the front of the net. He put the puck past Leafs netminder Frederik Andersen while simultaneously getting a shove from former teammate Ron Hainsey that caused Dumoulin’s shoulder to make contact with the goalie’s helmet.

Goaltender interference. pic.twitter.com/yaDLGqAetW

— Pittsburgh Penguins (@penguins) March 11, 2018

Referee Dean Morton not only waved off the goal, but assessed Dumoulin a two-minute penalty for goalie interference. That meant the Penguins couldn’t even use their coach’s challenge on the play.

Less than 30 seconds later, what could have been a 3-1 game became a 4-0 blowout when Toronto’s Mitch Marner cashed in on the power play. When the Penguins later scored two to close the gap to 4-2, Dumoulin’s no-goal and subsequent penalty loomed large.

“I disagree with the call,” Penguins head coach Mike Sullivan said. “They see it a certain way out there. I do think the call should be challengeable, because it’s a turning point in the game. It’s a two-goal swing. And, based on everything that I watched and saw, it looked to me like it was a good goal.”

It’s an issue that’s been coming up all year long. And it’s not getting any clearer as teams head toward the postseason.

“It’s obviously a huge issue in the league; it seems like every week this issue gets raised,” Sullivan said. “It’s a challenge the league has to try to iron out. I know it’s being discussed, and everybody’s got to try to do their best to clarify the language and criteria or whatever it may be. Because, right now, I don’t think anybody really knows what’s goalie interference and what isn’t.”

So what is goalie interference, anyway?

If it seems like the goaltender interference rule isn’t well-defined, rest assured that the NHL has put an awful lot of words around it. In the 2017-18 rulebook, you can find four pages (94 through 97) dedicated to Rule 69, Interference on the Goalkeeper. The spirit of the rule, essentially, is to protect goalies and allow them to play their position:

“A goalkeeper should have the ability to move freely within his goal crease without being hindered by the actions of an attacking player. If an attacking player enters the goal crease and, by his actions, impairs the goalkeeper’s ability to defend his goal, and a goal is scored, the goal will be disallowed.”

Also related are Rule 78.5, Disallowed Goals (114), and Rule 78.7 (ii), Coach’s Challenge, Scoring Plays Involving Potential “Interference on the Goalkeeper” (116-117).

In case that leaves any confusion, Table 16 dedicates six pages (150 through 155) to explaining various goalie interference scenarios and how to handle them. Dumoulin’s situation would seem to fall under scenario 1C:

“An attacking player makes incidental contact with the goalkeeper at the same time a goal is scored. Goal is disallowed. The official in his judgment may call a minor penalty on the attacking player. The announcement should be, ‘No goal due to interference with the goalkeeper.’”

That sounds about right, except that Dumoulin’s incidental contact with Andersen happened because of a shove from the goalkeeper’s teammate.

“I thought if there was any contact, it was after it went in,” said Penguins captain Sidney Crosby. “It’s obviously easy to say that after you see a replay, but it’s a big play in the game.”

Even Dallas Stars captain Jamie Benn, watching the game in Pittsburgh as he waited to face the Penguins the following night, had thoughts.

https://twitter.com/jamiebenn14/status/972652180841824257

The league is reportedly about to put some additional words around the rule – specifically from Colin Campbell, head of NHL Hockey Operations, instructing players and coaches to stop airing their gripes about it.

“There’s a feeling at the league office that this is not something that’s productive to the process whatsoever, the amount of complaining that’s gone on about it,” Sportsnet’s Mike Johnston said. “So there will be a continued discussion…but certainly the message will be, ‘Don’t air your public laundry here to the press.’”

That suits the Penguins just fine.

“I don’t give it much thought as a coach,” Sullivan said. “We control what we can, and the league’s going to do their best to try to iron it out. We’re just going to coach our team.”

Both Sullivan and Crosby agreed, though, that an easy improvement would be to make the call challengeable, even if the officials call a penalty on the play.

“I think that’s just common sense,” Sullivan said. “It gives the referee a second look at it, because it happens fast.”

“Everyone’s trying to do their best,” Crosby said. “As players, we’re trying to stay out of the blue paint.  I’m sure officials are trying to get every one right. The tough [thing] about that one is we end up getting a penalty, so we can’t even challenge it. Ideally, we would’ve been able to challenge that and maybe it goes the other way.”

‘We don’t understand the rules’

About the only thing that is clear about goalie interference right now is that everyone is unclear about how it’s being interpreted and enforced.

“We have no idea what’s going on in this league,” said Penguins center Evgeni Malkin on Feb. 24, after linemate Patric Hornqvist had a goal waved off against the Florida Panthers. “We have no idea of the rules right now. It’s not just our team. I think it’s everyone – coaches and goalies. We don’t understand the rules.”

That’s a goal of the annual GM meetings later this month in Florida, according to an email from Campbell and Bill Daly, the league’s deputy commissioner, to the Toronto Star.

“To the extent there is any current confusion, hopefully everyone will be on the same page coming out of that meeting,” Daly said.

“We too want consistency,” Campbell added, “particularly in the playoffs, with so much on the line.”

And that’s why the league must break with its own traditions and implement in-season changes to the rules – and/or clarify the language around existing ones – before goalie interference swings a postseason contest or best-of-seven series.

Because, at the rate it’s happening, that’s not an if, but a when.