Let’s cut to the chase and answer the title question of this post bluntly: you don’t.
The Bruins’ “Perfection Line” of David Pastrnak, Patrice Bergeron and Brad Marchand may have one of the most absurdly hyperbolic nicknames in the history of sports, but they also have the skill and at least some of the results to make good on the moniker.
And they’ve been a handful for the Caps all season long.
In seven games against Washington, the trio in 64 minutes of five-on-five hockey has outscored the Caps 9-3, more or less in line with their 70.6 expected goals-for (xGF) percentage, 68.4 Corsi-for (CF) percentage, 66.0 scoring chance-for (SCF) percentage and 75.0 high-danger chance-for (HDCF) percentage (stats per NatStatTrick), all despite starting more shifts in their own end of the rink than in the offensive zone. They have an on-ice shooting percentage of 20 percent (but only an .842 save percentage).
Needless to say, it’s going to be critically important to the Caps’ success for Peter Laviolette to get his best match-up out against the Bruins’ top line as often as possible. The thing is... he doesn’t necessarily have great choices there. Let’s take a look at how every Cap that has played 15 minutes against the line has fared this season. Warning: it’s ugly.
There’s not a whole lot to like there, from Alex Ovechkin being outscored 6-0 in just 21 minutes, to Nick Backstrom’s 16-3 shot attempt deficit, to Boston holding an 8-0 edge in high-danger chances (and 20-5 walloping in all scoring chances) with John Carlson on the ice. Does Peter Laviolette try to use his fourth line against them because they “held” the line relatively (key word: relatively) in check? Dmitry Orlov (as he often does) looks like a best bet on defense... despite he and Carlson allowing two goals against the trio in just six minutes of work this year.
Small samples, of course (so small that guys like Lars Eller and Trevor van Riemsdyk don’t even make the ice time cut here... but you’re not missing much there).
So what’s the answer?
There isn’t one. It’s the classic “you can’t stop them, you can only hope to contain them.” And one way to contain them is by knowing how they like to play and game-planning accordingly. For example, thanks to Corey Sznajder’s incredible work (go and support him on Patreon), we see that Pastrnak is the one of the three most likely to be carrying the puck in...
... while Bergeron is more likely to be the first forechecker in on dump-ins (and Marchand is somewhere in between the two):
There’s a reason the right side (Pastrnak’s side) of this heat map is as red as Capital One Arena in late-May/early-June of 2018 (and there’s also a reason that Alex Ovechkin - a defensively indifferent left wing opposite Pastrnak - was outscored 6-0 by this line):
Whether it’s creating his own chances off the rush or via the forecheck/cycle work of his linemates, Pastrnak is the focal point of the trio’s offense... but all three are comfortably above average in shot generation in either style:
Pick your poison, but the Caps would be wise to shore up the left side of the ice against the Bergeron line and try their best to throw a net around Pastrnak. That likely means as little Alex Ovechkin, Brenden Dillon and Zdeno Chara as possible (of course, these will be the guys Bruce Cassidy will be targeting). Otherwise, there might be a lot more of this:
Assuming that everyone’s available, the Caps’ best bet is probably to get Eller, Conor Sheary and (just guessing) Michael Raffl and Dmitry Orlov out against them, and hope that the Caps’ top-six forwards can more than compensate for the deficit the team will be running by beating Boston’s other nine forwards (no small task in and of itself). In other words, the “Perfection Line” (or, as Laviolette would prefer, the “Bergeron Line”) outscored the Caps 9-3 at five-on-five in seven games during the regular season. If they put that same thumping on the Caps over seven games starting Saturday, is it reasonable to think the Caps’ could outscore the Bruins’ other three lines by the same margin? It’s a tall order, but maybe. And, of course, it’d be nice for Caps goalies to stop more than 80 percent of the shots they see from the trio; that doesn’t seem like too much to ask (and the offense taking careful care of the puck at the offensive blueline would help).
The bottom line here is that the Bruins’ top line is going to get their goals and will almost certainly be a net positive for Boston. But if the Caps can limit them and beat them elsewhere down the lineup, they’ll have a chance. Otherwise, things could get ugly, fast.