NOBODY'S BACK TO COVER THE girl who's breaking downcourt past the defense. The guy inbounding heaves her a long pass. She takes it, dribbles twice toward the basket, stops about 10 feet out and gathers herself to shoot. She does it the way people who have been trained do it, releasing her shot in a smooth unbending of the body that starts in her ankles and carries through to her wrist and fingertips. The net gags, then swallows the ball.

Other women have played with these guys in the nightly pickup game on the fifth floor of the downtown YMCA, but only Betsy Gillespie keeps coming back. It's a serious crowd, and the game is physical. The athletic wear is street-level U.S.A. "LEAVE ME ALONE!" reads one T-shirt. "By Any Means Necessary" reads another.

"Yeah, there was some intimidation at first," says Gillespie, who's in her early twenties and teaches fifth grade at Our Lady of Perpetual Help in Anacostia. "They test anybody new. Sort of exclude you from the game until you steal a ball or take a tough shot -- anything to let them know you're not intimidated. Then you get in the club."

Gillespie, who's 5 foot 8, played girls basketball at Bethesda-Chevy Chase High and varsity field hockey on scholarship at Duke. After earning a degree in international relations, she decided that she wanted to teach in the inner city. She promised herself she would stick it out at least two years, as she would a Peace Corps tour. "I'm still really idealistic," she says at the end of her first year, though she admits she's frustrated by how much of learning and life's opportunities her 11-year-olds have already missed. Some days she can hardly wait to get to a place where that frustration finds an outlet.

"She's a good ball handler, a good outside shooter," says Laurence Walters, a regular, six feet tall. "She doesn't back down."

"I'd rather have her on my team than a lot of guys out there," says Mike Johnson, 6 foot 3. "If you leave her alone, she will bust you."

Gillespie recalls a couple of moments that let her know she was in the club. Once, she took an elbow to the cheek that drew blood, had to be iced and forced her out of the game. She surprised the guys when she came back the next day, and they took it easy on her until she told them to stop. It seems they were touched by her toughness.

Another time, learning that she'd split with her boyfriend, who also plays at the Y, several of them asked if there was anything they could do to help get them back together again. She was touched by their gentleness.

She smiles as she talks about the strange niche she has won for herself. "It's odd," she says. "I don't think about my sex anymore when I'm out there. I like that. I trust them."