Todd Reirden refers to them as set-up shifts. They're the shifts that don't necessarily end in a goal being scored, but they lay the groundwork for an eventual lamplighter, perhaps as soon as the very next shift.
A mid-December encounter in Tampa Bay provided an example. Midway through the first period, Washington's fourth line of Brendan Leipsic, Nic Dowd and Garnet Hathaway went to work on the forecheck. Having already pinned the Lightning deep in their own zone, the Capitals forwards hounded the puck and kept the Lightning from breaking out. As the pressure mounted, one Capital at a time successfully headed to the bench for reinforcements.
Moments later, with the Lightning still caught in their end, defenseman Jan Rutta turned the puck over and Nicklas Backstrom buried it from in close. The Capitals had a 1-0 lead en route to an eventual 5-2 win.
"The importance of a fourth line is to be able to affect the other team's best players," Reirden later said. "They forced the defensemen on the Lightning to stay on the ice for 1:12, playing in the D zone after we forechecked them. We changed and got Alex Ovechkin and Nick Backstrom on the ice versus a defenseman that had been on the ice for 1:12. Alex stripped him from behind and Nick got a freebie."
While none of Leipsic, Dowd or Hathaway was on the ice when the puck went in, their hard work paid off. The investment had been made. And as Reirden notes, "That's the effect a fourth line can have. For me, it was a set-up shift."
The Capitals feel they set themselves up for success this season by building a workmanlike fourth line over the summer to complement the high-end talent already in place.
As the Capitals reached mid-February in their familiar perch atop the Metropolitan Division, the consensus with the fourth line is that they've provided exactly what Reirden and general Brian MacLellan envisioned last offseason.
"I think we wanted a different identity on our fourth line, was the main goal," MacLellan says. "We wanted a combination of everything- the ability to penalty kill, score a little bit and be physical. I think we've found it in Leipsic, Dowd and Hathaway."
Video: FLA@WSH: Leipsic goes five-hole
Dowd and Hathaway have emerged as key cogs on the Capitals' vastly improved penalty kill - the unit ranks third in the league after finishing last year ranked 24th - while Leipsic has provided some welcome speed and skill to the revamped fourth line.
Collectively, they have quickly meshed as a trio that has brought intensity, simplicity and plenty of positive momentum.
"The opposition doesn't really like playing against them, so now you've got [opponents] off their game a little bit," Reirden says. "I think they've been a real strong point and we'll continue to need them and use them in that capacity."
Hathaway signed a four-year deal last July and has come as advertised. The 28-year-old winger is among the NHL's leaders in hits per 60 minutes and has shown a tremendous knack for getting under the opposition's skin. Hathaway leads the Capitals with a team-high 31 penalties drawn and he is tops across the league with 3.12 penalties drawn per 60 minutes (min. 25 games played).
"He's one of those guys who you want to win with and who you want to win for," says Tom Wilson. "That's what you need in a locker room and that's what you need with a winning team. He's stuck up for us in different situations and that goes a long way."
Hathaway earned plenty of praise from his coaches and teammates after an early-season home win over the Rangers. In that particular game, Hathaway suffered a broken nose, fought New York's Brendan Smith, drew a penalty that led to an eventual power-play goal and ultimately sealed the win with an empty-net goal.
"I've loved being here," says Hathaway, a Brown University alum who joined the Capitals after four years in the Flames organization. "The transition was pretty seamless. The guys in the room have been great, it's made the transition very easy."
Together, Leipsic, Dowd and Hathaway have emerged as a trio that can be trusted defensively and have taken advantage of their opportunities.
Through the first 56 games of the season, Washington's fourth line had produced nine goals while allowing six (60.00 goals for percentage) and 126 shots on goal while allowing 82 (60.58 shots for percentage) in nearly 235 minutes together at five-on-five. They recently went 17 consecutive games without being scored on at even-strength.
"I think the three of us are responsible defensively," Dowd says, "so if we are put in situations where we have to defend, we feel comfortable doing that. We don't mess around with pucks in the neutral zone- we get pucks in deep and we forecheck. I think we've been really successful at turning 50/50 pucks into possession and zone time."
While Dowd signed a three-year extension last summer and Hathaway is signed through 2023, Leipsic is playing on a one-year pact. After bouncing around five different teams over the past four seasons, Leipsic says he's benefitted from a defined role in Washington. He's been a fixture as the fourth line left winger with consistent linemates.
Video: Postgame | February 13
"This is new for me," Leipsic says. "The last two years before this were pretty choppy. I was in and out of the lineup- traded, [claimed off] waivers, moved in the expansion draft - so I'm not taking anything for granted right now. It's  games here and I've been able to play every one so I'll look to keep it going."
Despite seeing time in the NHL with four other teams, Leipsic has never played in the Stanley Cup Playoffs. While he's looking forward to potentially making his postseason debut this spring, his personal experiences have taught him to stay cautiously optimistic.
"I take it day by day because I've seen it all" he says. "Until you're on that roster after the trade deadline, nothing is set in stone. So, I'm still trying to prove myself every day. But having been a part of this group so far this year, it would be an awesome experience to get to play in the playoffs."
And based on how the fourth line has looked for much of the regular season with their combination of tenacity, grit, physicality and energy, it's a trio that could emerge as a difference maker as the games grow in importance.
Video: SJS@WSH: Dowd finishes feed from Leipsic off the rush
"The biggest thing with the three of us," Dowd says, "is that we work hard and then our skill will take over as we get more and more shifts and we get more and more o-zone time. We don't do it the other way. We don't go out there and try to make skill plays early and then try and work hard after that
"It just boils down to staying consistent, getting pucks in and making plays from there. Everything is going to tighten up as we get closer to the postseason. I think if we're doing it now and we've been getting better at it throughout the year, that only bodes well for the postseason."
Consider the regular season the set-up for what could potentially be the Capitals' secret weapon come springtime.
Video: WSH@SJS: Hathaway sweeps up own rebound