Now everybody, including the Milwaukee Brewers, knows for a certainty what the Baltimore Orioles have suspected for weeks.

It's probably going down to the wire in the American League East -- a genuine blood-and-guts pennant showdown between the two clubs with the best records in baseball.

Lines outside the Baltimore ticket offices were more than 1,000 people long today, according to the Orioles. Was it just a week ago that owner Edward Bennett Williams, gazing at a three-quarters empty Memorial Stadium, said with asperity and humor, "All you need is to win 100 games every year, never have a rainout and you can break even in Baltimore."

Anyone who wants to know the source of baseball's power need only pay close attention for the next week. What we have is a counterpoint of sweeping broad-brush drama and trenchant, if camouflaged, detail.

Many will focus on the flashy contrast between these teams. Watch the formidable but flawed Brewers as they try to escape the professional humiliation of blowing a 7 1/2-game lead to the unimposing yet persistent Orioles. The juxtaposition of managers -- Earl Weaver and Harvey Kuenn -- is also catchy. The former is retiring at the height of his fame and prestige; the other, a former batting champion, is the silent, kindly man who's survived cancer, a heart attack and a leg amputation, yet must now endure the second-guesses that torment any rookie manager.

However, to those close to the teams, such considerations hardly seem likely to be the determining factors in the final act of this race.

What will the Orioles and Brewers watch most closely this week?

As the Orioles begin three games here on Tuesday, they're most concerned about the tangled pitching picture that attends seven games in six days, plus a possible playoff next Monday in Milwaukee.

Weaver could start Storm Davis against the Tigers on Thursday, then use Martinez, McGregor, Palmer and Flanagan (in that order) against the Brewers. In other words, keep the rotation intact, but stick in the rookie in Detroit. This would be the "percentage" decision, although it might mean starting Davis in a playoff.

Weaver's not planning to do any such thing. He's got ideas. Here's his plan.

After McGregor takes his turn Tuesday, Weaver will jump Palmer ahead of Flanagan in the rotation on Wednesday. That way, Palmer gets two last-week starts, both with three days rest; also, if the season comes down to the final Sunday, he wants Palmer on the mound.

Next, let Flanagan pitch Thursday and hold Davis for Friday. This is radical. Who but Weaver would go out of his way to welcome the Brewers to Baltimore with a 20-year-old rookie pitcher?

First, Weaver knows Flanagan beats the Tigers. Second, Flanagan, a veteran, could start a Monday playoff. Third, Flanagan has trouble with the Brewers, so, not having him pitch this weekend is no great loss. Fourth, the Brewers are .100 better against left-handers than right-handers, so why not throw right-hander Davis at them. Finally, fast ball specialist Davis might be tough in the twilight.

Kuenn has made the opposite decision. He's staying with his rotation. And that's a gamble. Kuenn's least formidable starters, Doc Medich and left-hander Bob McClure, now start in Fenway Park, the southpaws' graveyard, on Tuesday and Thursday, against Boston's Chuck Rainey and Dennis Eckersley.

By staying in rotation, Milwaukee also gets only one more start for Pete Vuckovich -- not two, as Weaver has managed for Palmer. The Brewers will have their four best ready for Baltimore -- Mike Caldwell, Vuckovich, Medich and Don Sutton (in that order). But they might be stuck with McClure in a playoff.

It's complicated. And, if wild things start happening in the standings, it could change. But those are the master plans now.

Both teams have other worries. How demoralized are the Brewers after blowing a gilt-edged chance to bury Baltimore either Saturday or Sunday?

"They wanted to get back in it, and now they are back in it," said Caldwell.

"It sort of makes Earl (Weaver) look like a prophet," said Paul Molitor in the Milwaukee papers. "He was talking about their winning the next two and what would happen . . . Now they're still in a position to snatch it back from us."

The Red Sox have their three least-awful starters waiting for Milwaukee, including John Tudor (13-10) on Wednesday. And, Boston is a .618 team at home. However, the Brewers love bandbox road parks after the frustrations of spacious County Stadium. That's why Milwaukee has 25 more homers on the road than at home this year.

The Orioles have a history of late-season stumbles against nondescript teams. In '77, two late-September defeats in Cleveland hurt badly. In '80, a pair of losses in Seattle turned a comparable comeback push sour. Also, the Tigers have Dan Petry and Jack Morris waiting for the Orioles here.

But the Orioles have a couple of scores to settle with Detroit from last week; the scores were 10-5 and 11-1. The Orioles love to hit in Tiger Stadium, the Detroit staff is gopher ball prone and the Orioles buzzed in Milwaukee about how the middle of the order seemed to have found their power strokes.

In a nutshell, here are the week's three most likely possibilities.

If the Orioles lose one game in the standings in the next three games, they would have to sweep all four games to gain the pennant.

No such thing has ever happened.

If Baltimore stays two back entering the weekend, it would have to win four of five, including a playoff in Milwaukee, to win the AL East.

It probably couldn't.

But, if Baltimore gains one game over the next three days, the Orioles could win outright by taking three of four in a park where they play .649 ball.

And, considering Baltimore's confident play against Milwaukee this year, that would not stretch credibility in the least.