Ethel Johnson was ecstatic. She waved her arms, pedaled her legs and chortled her winner's chortle until a guy four rows away asked her to please keep it down. But Johnson was entitled, and she knew it.

"I told them that 4 horse. Told them and told them again," she said, as she gazed at the winded animals who had just finished the seventh race at Rosecroft Raceway, and at the $27.40-for-$2 payoff flashed on the tote board. "Now I get the money and they get to cry."

Earlier that day, Louis Smith had also been sitting in a racetrack grandstand. He, too, had correctly picked the No. 4 horse to win the seventh race, and he, too, felt like doing a little bragging to the disbelievers nearby who had invested in some other horse.

But where Ethel Johnson goes to Rosecroft Raceway in Oxon Hill twice a year, Louis Smith goes to Pimlico six days a week. So Smith knew what most of Pimlico's serious-minded regulars know -- that picking one winner, or bragging about it, will not turn a lifetime of red ink to sudden black.

"The guys at this track know the ropes," said Smith. "What they know is the rope is mostly around your neck. With a knot in it."

The contrasting attitudes reflect the two extremes of Maryland's spring racing season, now in its final days. Rosecroft is a harness track in suburban Oxon Hill, where a youngish, principally black crowd goes mostly as an alternative to an evening at a nightclub or the movies. The atmosphere is comfortable, the betting recreational. Pimlico, except for this Saturday, when the Preakness brings its annual crowd of outsiders and celebrities to the well-worn track in northwest Baltimore, is a serious place, where the horses are thoroughbreds and the crowd mostly white, male, and 55 or older.

The difference between Rosecroft and Pimloco is literally night and day. Post time at the 32-year-old Rosecroft, nestled in a grove of oaks just a few hundred yards from the Capital Beltway, is 8 p.m. The first race at 111-year-old Pimlico, nestled in a grove of red-brick town houses, is seven hours earlier, in broadcast daylight.

The result? "We get the people who bring their wives and girlfriends here instead of taking them to the Bullets or the Caps, or a concert," says William (Pete) Shaw, Rosecroft's general manager. "We get solid, working people from all levels of society who want a night's entertainment."

At Pimlico, however, "I'm always passing guys who I wonder, 'Have they paid their heating bill?'" says Morty Mittenthal, the track's director of bettor relations. "I'd say at least half of our patrons are retired or unemployed. And I mean at least."

The horses may look alike at the two tracks, but as social environments, where strangers share a sporting passion, Rosecroft and Pimlico could hardly be more different.

At Rosecroft, "people come, they bet a few bucks, they seldom talk to anyone they didn't come with, and they go home," says Earle Palmer Brown, the track's president. Indeed, unlike many tracks, there are nights at Rosecroft where passions run so low that only a handful of fans cheer the horses around the final turn and into the homestretch.

Because the average crowd of 4,800 a night is so varied -- octogenarians with canes, teen-agers in high school baseball team jackets, U.S. senators, dump-truck drivers -- "You very seldom see a group of 10 spontaneously sitting together in the grandstand," says Willie Adams, and Oxon Hill resident who says he comes to Rosecroft three or four nights a week.

The one exception is the plaza underneath the lower grandstand. The regulars there are almost all black. They jokingly refer to "their" area as "The Back of the Bus."

Here, on park benches, Ethel Johnson met Livonia Stewart before the first race one recent Friday night. By the seventh, according to Johnson, the two women had become "real good friends."

"They don't sell chitterlings down here," says Stewart a resident of Capitol Heights who has been a Back of the Bus regular since 1967. "But black folks know they'll feel comfortable here. Black folks say hello to strangers who are also black folks here the same way they would in the subway." s

According to Shaw, nearly 60 percent of Rosecroft's grandstand customers are black.

At Pimlico, fewer than 8 percent of the customers are black, according to Mittenthal. But the Pimlico crowd splits according to the familiarity of faces, not their pigmentation.

Sit down next to a random fan in the upper grandstand, and if he recognizes you as a regular, he is odds-on to ask you within five minutes how you're "making it" (translation: "Are you winning or losing?"), and who you like in the next race.

And the camaraderie can sometimes extend even further. "I've seen people who've tapped out [run out of money] go up to someone whose face they recognize, but they don't know a name, and borrow a few bucks to get home," says Bernie Grubitz, the usher in Section 1 of the clubhouse reserved seats.

"And they get it back the next day," says Grubitz. "It's honor among horseplayers or something."

Nor is enthusiasm lacking at Pimlico. The din of railbir their choices can be heard as far as a 7-Eleven parking lot three blocks away.

Even Mittenthal cheers. During a race one recent afternoon, he politely interrupted a calm, thoughtful interview to ask if his visitor would "mind me rooting them home." Assured that it would be all right, Mittenthal suddenly rose to his feet, rolled his program into a baton and started shouting: "C'mon, Arnie! Ride that horse, Arnie!"

To walk into Pimlico or Rosecroft is to see differing styles of commerce within the first 10 strides.

Just inside the Rosecroft clubhouse entrance, the program vendor cries, "Program and lucky pencil, right here!" Off in a corner, teen-agers and elementary schoolers brought by their parents play video pinball games. Behind a partition, and woman sells Rosecroft memorabilia -- jackets, caps, shorts, even a crying towel. The atmosphere is akin to a county fair.

At Pimlico, the first vendor that an arrival encounters is selling heaping mounds of the Daily Racing Form. The vendor sells pencils, too -- "but I'd be laughed out of town if I called them lucky," said Ike Eisenberg, who works the grandstand entrance. "My customers don't really believe in luck, I don't think." Nor are there video games at Pimlico. "Those just wouldn't interest our people," explained Mittenthal.

Where some sections of Rosecroft do not even offer $50 minimum betting windows, it is common to see bettors dash for the $50 windows at Pimlico just a minute before a race goes off -- their fists full of hundred-dollar bills. And while Pimlico also sells memorabilia imprinted with the track's name, Darlene Eberhard, who works the grandstand souvenir counter, says that only Preakness day brings heavy sales.

The bottom line marks Pimlico as the home of the higher roller. Pimlico averages about 8,000 customers a day, a little less than double the Rosecroft average. Yet this year's average "handle" -- or amount bet per day -- is about $1.1 million, nearly triple the Rosecroft average.

Among the strongest Pimlico loyalists are about 35 Washingtonians who board an 11 a.m. bus at the downtown Greyhound terminal every morning for the 75-minute, $3 ride to the track.

Carl Arthurs, a retired janitor who worked at the Pentagon, usually stops at the nearby Burger King on his way to the bus, where he buys two coffees to go -- one black for himself and one extra light for Sam Cortese, who worked until his retirement three years ago as a waiter at "one of Washington's best restaurants."

The two men know almost nothing of any consequence about one another -- not phone numbers, not addresses, not political views, not totals of grandchildren. pYet they see each other every day on the Pimlico bus, and they consider each other close friends.

We share something," explained Cortese. "And we both prefer Pimlico. It's got a feeling about it that no track around Washington gives you."

But feeling is one thing, and action is another. Different as Pimlico is from Rosecroft, Cortese is a regular at both. In fact, he often drops down to the clubhouse entrance just before the last race at Pimlico, where he knows he can find "the guy in the brown jacket," who sells that night's Rosecroft program.

The $3 bus ride home to 12th Street and New York Avenue NW allows just enough to study that night's Rosecroft card. And the 6:45 arrival time is a convenient 15 minutes before the next bus -- the one for Rosecroft -- leaves.