The group trying to bring Major League Baseball to Loudoun is asking for the kind of sacrifice from Washington area fans that no other major league owner calls for: a trek to outlying suburbs.

The proposed ballpark site in Loudoun County is about 21 miles from downtown Washington, a trip that in rush hour can take more than an hour.

No team in baseball plays its home games so far away from its region's major downtown, according to a survey of teams.

"It's a silly place," said E.M. Risse, a longtime Virginia planner. "It's not the center of anything. It's at the edge. It could be the town center for Dar es Salaam."

But proponents of the Loudoun location -- being touted by a business group that wants to bring the Expos to Northern Virginia -- say the site has advantages that are political, financial and geographical.

Because it is farther from Baltimore than other more centrally located Washington sites, proponents say the Loudoun property would allow baseball's Baltimore Orioles more opportunity to continue to tap Washington area fans. Orioles owner Peter G. Angelos has objected to relocating a team to the Washington area for competitive reasons.

Moreover, Loudoun boosters say measuring its proximity to downtown Washington is not the right way to gauge the site's appeal. While fans from all across Washington have longed for a major league team, the investor group has promoted Northern Virginia as the core of its market.

"This is not far out," said Bill Collins, head of the investors group, speaking of the Loudoun site. "If you live here, this is the epicenter of this marketplace."

Jerry Burkot, an executive with the investors, pointed to marketing studies showing 1.2 million people living within 10 miles of the Diamond Lake site, and more than 2 million within 20 miles. There are also 650,000 jobs within 10 miles, and nearly a million within twice that distance.

"If you're going to call that the boondocks, I'll take that every time. That's an uninformed and biased opinion, calling it that," Burkot said. "This is the fastest-growing county in the nation."

"People say workers from D.C. would be going to the suburbs to go to the ballgame. They're going there anyway, because that's where a lot of them live," Burkot added. "That's really the premise. When you're relocating a business, you want to be near where people work and where people live. . . . If they're on the moon, that would be the place to be."

Still, the Virginia baseball group's decision to focus on a site so far from the metropolitan center stands in marked contrast to other efforts in Major League Baseball.

The Virginia baseball group is vying against similar groups in the District, Las Vegas, Portland, Ore., Monterrey, Mexico, and Norfolk, to purchase the Montreal Expos from Major League Baseball.

The Virginia group had originally sought to build on other sites, including a handful in Arlington County, close to downtown Washington. Boosters touted the majesty of a stadium with views of the Washington Monument on the horizon. But without a final public hearing on the matter, the Arlington County Board issued a letter rejecting the group's overtures.

The Loudoun site, about 21 miles from downtown Washington and 10 miles from Tysons Corner, later became the primary site. Only two ballparks in the country are even roughly comparable in their distance from a central downtown. The Florida Marlins' Pro Player Stadium is about 12 miles north of downtown Miami, and the Texas Rangers' Ameriquest Field in Arlington is about 16 miles west of downtown Dallas.

All the other major league parks are within seven miles of downtown, and most -- particularly in the last decade -- have been built much closer to or within the downtown as teams have found advantages in central locations.

Many fans prefer such locations.

"I don't get all hung up on baseball traditions," said John Rawlings, editorial director of the Sporting News, which publishes The Ballpark Book. "But to me, it feels more right to go downtown for a baseball game."

The San Francisco Giants recently built a park on the city's downtown waterfront after considering a suburban location that offered more parking and better weather. But, team officials said, they preferred the city site because of its population density, high incomes, public transportation and the scenery it offered.

"We felt it was the best setting for a ballpark in North America," said Larry Baer, chief operating officer for the team.

But Dennis Howard, a professor of sports marketing at the University of Oregon, said an urban location doesn't make much difference to attendees.

"I don't think it's a significant impulse," Howard said. "I think what they prefer is easy access and drive time that is going to be within 30 or 40 minutes."

One of the chief reasons so many teams have located in cities in recent years, Howard and others said, is that cities have offered to help pay for ballparks. City politicians have touted new venues as a form of economic development, though whether they are worth the cost has been disputed.

The $360 million Loudoun stadium would be financed with taxes on ballpark-related spending, such as on food and players' salaries. Developers of an associated retail and commercial project would help underwrite costs, according to the stadium financing plan.

Collins said comparing the Dulles site with close-in stadiums in other parts of the country misses what makes the Washington area special. The bulk of the region's businesses -- and families -- are not in the District, where the federal government dominates, but in booming Northern Virginia, he said. Those demographic realities are beyond his control, and they make Tysons the comparable downtown, not Washington, he said.

"If I could put the stadium in the middle of Tysons Corner, I would have done it," Collins said. "It's impossible. There's no land."