It was a core component of all the Penguins accomplished in the early weeks of this season, a cornerstone of their surge to a 3-0-2 start.
And while there are no stats that truly quantify the effectiveness of a team's forecheck, there are a few numbers that seem to be directly linked to it.
Like goals scored. And games won.
For even though consistently pressuring opponents in their zone doesn't guarantee success -- witness the Penguins' 2-1 loss to the Sabres at PPG Paints Arena Tuesday night, when they were beaten despite making life miserable for Buffalo's defensemen at various points in the evening -- it does tend to enhance the chances of taking two points out of a given game.
A lot.
"It has a massive impact on the game" when a team is able to establish a strong and consistent forecheck, Jason Zucker said.
Of course, it also has an impact when a team isn't able to do that on a steady basis, which has been the case with the Penguins after the first couple weeks of 2021-22.
And while Jeff Carter said that "nothing's changed, except personnel a little bit, here and there," neither the forecheck nor the Penguins' won-lost record has been as impressive as it was in the first couple weeks of the season.
"Some nights, we're better at it than others," Mike Sullivan said.
Mind you, the Penguins have forechecked well at times, including against the Sabres, which is part of the reason they were able to generate 46 shots on goal.
"I thought we did a pretty good job tonight on the forecheck," Carter said. "They have some pretty mobile (defensemen) back there. ... I thought we did a pretty good job of getting in and turning pucks over."
The Penguins' forecheck probably was as crisp and assertive in the third period against the Sabres as it had been at any time in the previous 14 games, a reality that was reflected by their 20-3 edge in shots during those 20 minutes.
Only the play of goalie Dustin Tokarski made it possible for the Sabres to leave town with more than a little leftover meal money. That was particularly true during the final period, although he performed well enough throughout the game that he could have been named all three stars, instead of just No. 1.
"Third period was really ugly, from a team standpoint," Sabres winger Kyle Okposo told reporters. "And he won that game for us in the third."
Buffalo's focus then was on protecting the 2-0 lead it had built during the second period, but the Penguins were able to routinely get the puck deep into the Sabres' zone, then hound the defensemen who chased it down.
"It all starts with good puck placement," Zucker said. "You want to put it in places where it's tough for their (defensemen) to go back and get it and make a good play. ... A lot of people look at that as a mindless play, but in my opinion, it's a very skilled play. It's hard to make the puck sit in that corner and make the (defenseman) go back for it.
"If it sits there and you can get on him quick, it's going to be hard for any (defenseman) in the league to make a play. I don't care how skilled you are."
Of course, a goaltender who stops virtually everything sent his way -- the only puck that got by Tokarski caromed into the net off Jake Guentzel's skate -- can negate any errors in judgment or execution made by his defensemen.
Which is the best explanation for why the Penguins didn't get a tangible reward for the problems their forecheck created for Buffalo.
"I thought we were pretty effective at it tonight," Sullivan said. "We forced a lot of turnovers. We had a lot of offense-zone time, and we had a lot of puck-possession time. That, for me, is suggestive that we're playing on our toes and we're playing the type of game that we think gives us the best chance to win."
The kind they played so often when the season was getting started. And the kind they'll have to make a habit of playing if they expect to climb back toward the Eastern Conference playoff field.