updated 8:52 p.m. ET May 8, 2008

PITTSBURGH - Some NHL rivalries evolve from a big game, a major trade or a short-lived scuffle, then fade after a few years. Not the Philadelphia Flyers vs. the Pittsburgh Penguins.

This rivalry is real, perpetual, and, mostly, downright nasty.

Evolving from state lines and bloodlines — and it’s mostly bad blood — it’s been one of the league’s most heated since the teams were born in 1967. Now, for the first time, it will decide a Stanley Cup finalist as the Pennsylvania teams meet in the Eastern Conference finals beginning Friday night.

“All the games (during the season) were heated and now we go into the conference finals and I’m expecting it to be heated again, and even more,” Flyers defenseman Kimmo Timonen said.

Mimicking their locations in diametric corners of one of the East Coast’s biggest states, the teams are polar opposites. The Penguins haven’t advanced to the finals since 1992. The Flyers’ most recent appearance was 1997.

The Penguins, much like the days when Mario Lemieux and Jaromir Jagr were the team’s big names, are flash and dash, speed and flair with scoring stars Sidney Crosby, Evgeni Malkin and Marian Hossa. They’ve won eight of nine in the playoffs and all five home games, a relatively easy start for a youthful team whose three biggest stars, including goalie Marc-Andre Fleury, are 23 or younger.

The Flyers, while possessing multiple scoring lines like Pittsburgh, are rightful descendants of the franchise’s fabled Broad Street Bullies, winning through toughness and intimidation. They muscled up to the Penguins’ stars, pushed them around, distracted them with some success while winning five of eight during the season.

A season series that, on Dec. 11, required only 20 seconds for the first fight to start.

Eastern finals: Penguins lead 3-1      Which team has the Edge?  |  Schedule, stats Game 4: Flyers won't go away without a fight Video: Get the latest from around the league Impact players  |  Vote: Who will win? Clement: Flyers strike gold with Briere and Biron Opinion: Pens not on rise, they're already here Clement: Alex is great, but Sid still better Opinion: Malkin no longer NHL's best secret Clement: Roberts valuable to Pens’ chances Penguins page  |  Flyers page  |    Discuss Eastern Conference champions

Asked when the rivalry might kick in again, Penguins forward Ryan Malone said, “Probably right when the puck drops (Friday night), I think.”

Don’t think there’s a difference between the style of play in the usually free-flowing Western Conference and the rivalry-filled East? Consider this.

In their four regular-season games, Western Conference finalists Dallas and Detroit combined for 26 power plays and two power-play goals. In their eight games, the Flyers and Penguins combined for a remarkable 86 power plays and 20 power-play goals.

“I think the only difference in us that you’ll see from the regular season is that no one wants to take that extra one,” Penguins defenseman Rob Scuderi said. “It’s OK to be physical, it’s OK to play the body, it’s OK to play hard, but no one wants to take that extra penalty.”

Not with Philadelphia No. 3 and Pittsburgh No. 4 in playoff power-play scoring, with the Penguins getting at least one power-play goal in all but one game.

If there’s a common theme between Flyers coach John Stevens and Penguins coach Michel Therrien — who, coincidentally, faced each other twice in AHL playoff series — is that it’s as important for their teams to stay under control as it is to control the other.

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