And when they're behind, it rains.

That's how well the baseball fates are taking care of the Baltimore Orioles these days.

The Orioles trailed the Boston Red Sox here, 4-2, in the top of the third inning this evening when the faintest of rains--little more than a healthy mist--caused a cancellation.

The umpiring crew, headed by Bill Kunkel, waited 60 minutes before calling off the sparsely attended game. During the following hour, the New England drizzle varied from tepid to nonexistent.

"I'm so tired . . . let's go home," said catcher Rick Dempsey. "That was a tough series in New York (four games in three days). It kind of drains you emotionally. We can use a good night's sleep."

The Orioles' lead in the American League East was cut to five games when Detroit defeated Cleveland, 5-1, tonight. Baltimore still is up by seven in the loss column.

This game will be made up as part of a twinight doubleheader Tuesday, starting at 5:30 p.m. The Orioles will start Scott McGregor and Allan Ramirez, who were scheduled to pitch the second and third games of this series. The Red Sox will counter with Dennis (Oil Can) Boyd and a right-handed rookie named Al Nipper, who has pitched only one inning in his major-league career.

Boston's starters for Wednesday and Thursday's games will stay as planned--left-handers John Tudor and Bruce Hurst. The Orioles will stick with Mike Boddicker Thursday, but Wednesday's starter is very much "undecided."

Jim Palmer, who allowed four runs and four hits in the two wild innings he worked this evening, would be the first choice of Manager Joe Altobelli. Palmer would throw on Thursday, anyway, and after six days off since his last start, appeared this evening to need more, rather than less, work to be sharp.

"This is Palmer's year," teased Rich Dauer, meaning his ERA was saved from a bruising. Carl Yastrzemski crushed a 410-foot homer in the first after a walk to Wade Boggs.

In the second, Palmer walked the leadoff man, then allowed singles to Glenn Hoffman, Jeff Newman (first RBI since July 1) and Jerry Remy.

Although Palmer's delivery seemed out of sync (he had good speed but poor control) and his team was behind by two runs, many Orioles felt that it was simply a matter of time before they knocked out starter Dennis Eckersley, who allowed six singles and a line-out to the wall in facing 13 hitters.

Eckersley's ERA is 6.01, and of all the slumping Boston pitchers, he has been the worst recently. When his first pitch resulted in a hit, the crowd began booing immediately.

In the first, Al Bumbry, Cal Ripken, John Lowenstein and Ken Singleton had line hits, the later two for RBI. When the perspiration came, Ripken was on first with his second hit and one man was out.

Ripken, who has 172 hits, joked with teammates, "I hope I don't end up with 199 hits."