"It is a rivalry of similarity and proximity rather than difference and distance.

Baltimore and Pittsburgh are midsized cities on the water that are separated by a four-hour drive and the Allegheny Mountains. Both reached heights of prosperity in the Industrial Age and watched too many jobs ebb away in the late 20th century. Both have pinned hopes for the future on service and research industries and on downtown redevelopment.

And yes, both love pro football above any other sport. When the Ravens and Pittsburgh Steelers clash Sunday in their highest-stakes game ever, they will do so with a brotherly intensity.

Ravens linebacker Bart Scott calls Sunday's game "an opportunity for one of our organizations to really build up the level of hatred."

The feelings are reciprocated by Steelers wide receiver Hines Ward, a prime instigator in the feud. "There is nothing like beating Baltimore," he told Pittsburgh reporters after the Steelers did just that in December. "I love being the most hated guy" in Baltimore.

The teams share as many traits as the cities.

They play in the same division and have competed for control of it since 2000. Both are known for punishing defenses with penchants for big plays. Given his lack of a big-time college pedigree and dreams of starting a Super Bowl early in his career, Ravens quarterback Joe Flacco is practically walking in the shoes of his Steelers counterpart, Ben Roethlisberger. When the Ravens hired John Harbaugh, several wizened coaches said he reminded them of Pittsburgh coach Mike Tomlin-fresh-faced but comfortable exerting authority.

"It's two teams that play a certain brand of football," Harbaugh says. "Physical and fundamental."

Fans see the rivalry the same way.

"They know each other extremely well and the better of the two is usually the AFC North divisional champion," says Tony Lombardi, founder of the fan Web site Ravens 24x7. "The competitive, hard-hitting battles that result from the pursuit of that crown serve as the core of the rivalry, and the fans know it. Rivalries require competitiveness, and the Ravens and their fans know that every game against the Steelers is a brawl."

The view is similar from the other side of the Alleghenies.

"It's just natural," says Ron Cook, who has watched Pittsburgh fans warm to the rivalry as a sports columnist for the Post-Gazette. "The cities are very much alike, they're close together and the Ravens are the most threatening team in the division."

He remembers Steelers fans booing Ray Lewis at the 2006 Super Bowl during a roll call of former Most Valuable Players.

"They hate him," he says. "They hate his dance and everything about him."

The Pittsburgh-Baltimore rivalry packs plenty of back story.

One of the greatest football players Pittsburgh has ever produced, John Unitas, performed his greatest feats in Baltimore. Worse, the Steelers had Unitas and cut him. That blunder contrib"