They believed Baltimore's major league future was at stake. In the winter of 1987, the champions of a new downtown stadium for the Orioles had their best, and maybe last, chance to win state approval for a new Camden Yards ballpark.

They were prepared for a brutal fight.

But in April 1987, the stadium legislation glided to victory.

And Oriole Park at Camden Yards will officially open two weeks from today.

How did the project, which had been considered wildly controversial and the source of so much anxiety for its backers, turn out to be such a winner?

Like the alignment of some lucky political stars, several forces came together that spring to help propel the project through the Maryland legislature. It wouldn't have happened a year earlier. With the current budget crisis, it couldn't happen now.

The three biggest factors:

* The stinging memory of Robert Irsay moving the Colts football team out of Baltimore in 1984.

* The worry that Orioles owner Edward Bennett Williams, long battling cancer, would die, leaving the team to heirs who would sell it to owners who felt no allegiance to Baltimore.

* The political power and popularity of William Donald Schaefer, fresh from a big November victory, bringing his do-it-now reputation into his first year as governor.

Mr. Schaefer had dreamed of a Camden Yards stadium since the early 1970s, when a commission appointed by then-Gov. Marvin Mandel had praised the site. Now, Mr. Schaefer feared that unless Baltimore had a new ballpark, Mr. Williams was ready to follow Mr. Irsay out of town.

He threw his political weight behind the project. The stadium became "the centerpiece of our legislative package," said Alan M. Rifkin, a lawyer and lobbyist who served then as Mr. Schaefer's chief legislative aide.

"It was important for the stability of the city to have a long-term lease," Mr. Schaefer said. "We started to say, 'We need a new

stadium.' "

The idea had many critics -- most notably taxpayers who didn't want public funds spent for a new sports complex when the city had Memorial Stadium.

But the Orioles had been in the hands of Mr. Williams, a Washingtonian, since 1979. And he had made clear that Memorial Stadium wasn't good enough. In 1984, Mr. Irsay, who for years had blustered about moving his team to another city, finally packed the Colts off to a domed stadium in Indianapolis.

"The intensity to keep the Orioles in the city was a direct result of the loss of the Colts," Mr. Schaefer said recently. "It was a psychological loss to the city, a very deep psychological loss to the city. When they [the Colts] left, the loss of the Orioles was always in my mind." So Mr. Schaefer lobbied. His legislative team managed to find a financing formula that hinged on lottery revenues, not new taxes. Still, Mr. Rifkin recalls, "The bill was flailing, near failure in my view."

The stadium backers knew they had to wow legislators at a big legislative hearing set for week's end. But the odds for victory, Mr. Rifkin thought, were dicey.

Then, Mr. Rifkin said, Mr. Schaefer delivered dramatic news. At a news conference a few days before the hearing, the governor announced that Edward Bennett Williams himself would testify at the hearing. Mr. Rifkin was elated.

The only problem was: No one had asked Mr. Williams to testify.

"I think you better call him," Mr. Schaefer told his legislative chief.

So Mr. Rifkin and his deputy, David Iannucci, had to call the Orioles owner to inform him that the governor had committed him to an appearance in Annapolis. Mr. Williams wasn't pleased. said he would be out of state the morning of the hearing. The scheduling was impossible, he told the Schaefer aides.

But the governor didn't seem disturbed. Mr. Rifkin recalled Mr. Schaefer saying: "He'll be there. He'll come."

Mr. Schaefer doesn't remember it that way. The governor said he would not have announced Mr. Williams' appearance without Mr. Williams' approval. Any other version is "a good story."

Herbert J. Belgrad, the stadium authority chairman, says Mr. Schaefer's announcement wasn't intended to pressure Mr. Williams into testifying but that there was a "breakdown in communications" concerning "the specific date the hearing would be held. My impression was the governor proceeded in good faith."

But until Mr. Williams walked into the Governor's Mansion on the day of the hearing, no one was certain he'd show. He had undergone cancer treatment that morning, and it had left him weak, unable to eat. Mr. Rifkin remembers worrying if Mr. Williams would make it through the afternoon.

He shouldn't have worried. When the hearing started, Mr. Williams, a courtroom veteran, was a star. For more than an hour, he deftly handled lawmakers' not-always-kind questions. He exuded power and authority. He was gracious, deferential, charming. He looked healthy, although everyone knew he wasn't.

Mr. Williams said he couldn't break even in a ballpark with as few "first-class seats" as Memorial Stadium had. "I'm not rich enough to operate a major league baseball team in the red," he told the delegates and senators.

He invoked the grim memory of the Colts: "I believe the darkest day in sports was when Mr. Irsay backed his trucks up and fled into the night and took the Baltimore Colts with him." And, off-handedly, he even noted that one day he would no longer be there to protect the team. "In the event that I die " he began one answer.

The hearing was the turning point. Within a month, the project was approved.

Today, the stadium legislation probably would not even be proposed.

"You have a completely different climate," Mr. Rifkin said. "The economic landscape is far different than in '87. The recession has tempered people's enthusiasm for items that are not considered to be necessary. The 1990 election brought, in my view, a more fiscally conservative group of legislators to Annapolis. The governor . . . was at his zenith of political power after the initial mandate in 1986."

Oriole Park at Camden Yards opens next week, and the Orioles are safe in Baltimore for at least 15 years. The national prestige, the economic benefits, the panache that a major league team brings a city are secure.