That first-round playoff meeting in 1992? The one in which the Penguins spotted Washington a 3-1 lead before running off three consecutive victories en route to their second Stanley Cup?
Penguins defenseman Brooks Orpik doesn't know a thing about it.
Same with Round 1 in 1995, when the Penguins again rebounded from a 3-1 deficit to end the Capitals' season.
Likewise, the opening-round matchup in 1994, when Washington won its only playoff series against the Penguins in eight tries.
All are part of franchise history; all are news to Mr. Orpik.
"Besides the one I played in, I don't know any of the other ones, to be honest," he said.
Happily for him, that second-round series in 2009 -- when the Penguins lost Game 6 in overtime at home, then blew out Washington in Game 7 at the Verizon Center -- is one he isn't likely to forget anytime soon.
It took a rivalry that had existed, and been fairly heated, for years and elevated it into one of the most intense this side of cobra-mongoose.
And while neither team is a clear choice as the other's most despised rival, neither is far from it, either.
"They have to be right there, with Philadelphia," Penguins center Sidney Crosby said. "If not right there, a really close second. Personally, I would put those two teams right together."
Alex Ovechkin, Mr. Crosby's counterpart as Washington's captain and franchise cornerstone, sees the Penguins pretty much the same way.
"They're top two, I think," he said. "Philly, New York [Rangers] and Pittsburgh are our [rivals], especially for the fans."
The Penguins-Capitals rivalry is, in some ways, almost a subplot to the Crosby-Ovechkin story line that dominates conversations anytime these clubs collide. Guys like Kris Letang and Nicklas Backstrom, Evgeni Malkin and Mike Green, are top-shelf talents, but the spotlight rarely drifts from Mr. Crosby and Mr. Ovechkin.
"Ovie and Sid really heat up the rivalry," Washington forward Jason Chimera said. "Anytime those two guys get together, it's a good event."
Although Mr. Crosby is widely regarded as the finest player in the world at the moment, it hasn't always been that way. In fact, Mr. Ovechkin has won two league MVP awards, Mr. Crosby just one.
"They have maybe either the first- or second-best player in the league, depending on who you ask," Penguins winger Pascal Dupuis said. "And that makes for a good rivalry."
While Mr. Crosby and Mr. Ovechkin recognize, and perhaps even appreciate, each other's skills and intangibles, their relationship is every bit as prickly as would be expected from two ultra-intense competitors. On those occasions when they've been obliged to pose together for a photo, the smiles couldn't have looked more forced.
Predictably, their individual battle has been a major element in the buildup to the Winter Classic game between the Penguins and Capitals, set for 1:08 p.m. Saturday at Heinz Field. This will be the first time the teams have met outdoors, but that's nothing more than a footnote.
Fact is, the setting couldn't be any less significant. Put these teams on a miniature golf course or behind debate podiums or on a tennis court, and the competition likely would be as ferocious as it is on the ice.
They are "fun games against them," Mr. Backstrom said. "A lot of emotion."
Ah, the sweetness of undiluted hatred.
Capitals winger Mike Knuble knows a bit about the passion certain opponents coax out of a team. After all, he broke into the NHL with Detroit when the Red Wings' blood feud with Colorado was at its most fierce.
He also played in Philadelphia before joining the Capitals, and volunteered that "Philly-Pittsburgh was a real good rivalry, too."
Of course, it stands to reason that those two clubs would despise each other. Both entered the league in the 1967 expansion. They share a state. And a division.
None of that is true of the Penguins and Capitals. Doesn't seem to matter.
"I think Philly will always be No. 1," Mr. Orpik said. "But just from the time I've been here, I would say probably Washington and Detroit [are next in line]."
The Penguins occupy a similar niche when the Capitals rate their rivals.
"They probably rank pretty high," Mr. Backstrom said. "Probably, the biggest."