She has screamed in anger at women who beat her. She screamed at a woman half her age. You have no talent, she screamed after losing to her. No kinder than McEnroe at full rage, she has stormed linesmen. Playing doubles, she has fallen into silent sulks. She has walked off a court in mid-match.

She wants everyone to know she may be old now, may be heavy now, may have bad knees now. But once she could play the hell out of tennis. She has screamed it at women who beat her, and she has screamed it at herself.

"It's not a lot of fun," Billie Jean King said of losing. She doesn't like it any more at 38 than she did at 18. "I hate it. I'm a lousy loser, a lousy sport. I'm bad-tempered. I try to stay in sane, or near-sane, control."

It bothers her, she admits, that young players today may not know her historical importance. Once there was no women's professional tennis. Then, in 1967, she turned pro with three others. Now someone can win $1 million a year. Besides which, King played the hell out of tennis, played for 15 years the way she has played this week to reach Friday's semifinals of Wimbledon against Chris Evert Lloyd.

"I think it's nice that other players know you're good," King said. "I mean, great. I have to be honest. It's nice they know you were really okay at one time. I think everyone wants to be liked by the other players, but I don't think I am."

Why?

"They think I'm a hothead, a bigmouth."

For Billie Jean King, life is always at match point. She has won the point a lot of times: six Wimbledons, four U.S. Opens, almost $2 million on tour. She has lost some: a magazine failed, a tennis league died, tennis camps went belly up--and last year she admitted to a homosexual affair with a former secretary who claimed King promised she could live in her house forever.

Who knows what drives Pete Rose to hit .450 for a month after his wife walks out? Was it only a mad lust for perpetual fame that moved Muhammad Ali to fight Larry Holmes? Perhaps when life goes bad, these men hide in their games. And if an aging tennis champion at match point needs the comfort of familiarity, what better place than Wimbledon?

Come Friday afternoon here, King will curtsy for the Duchess of Kent. Astonishingly, she plays a Wimbledon semifinal 21 summers after first setting foot on the Centre Court stage that has defined her life in three decades now.

"I'd like to see films of Billie Jean from the '60s," said Evert, paying homage.

"Chris was a baby," the old champion said.

It was 62 years ago when a woman older than King last reached the semifinals here. No one 38 ever won the championship. As with Rose and Ali, with King the story is more than what the aching body has done. The story is what the mind has done.

"At 38, you go, 'Who needs this?' " King said, trying to explain the price of pain payable on demand when your knees have been fixed by doctors five times. "You go, 'I've already been through it 20 years. Why should I go out running today? Why should I do two-on-one drills today? Why should I go do my weights tonight? I don't feel like it.'

"And at 38, you say, 'I've earned it. Let's go have a beer.' "

King turned down the temptations of middle age. She ran, lifted weights, played tennis with two people on the other side of the net. She lost 20 pounds. And when the women's tour bosses called and asked her to play in Detroit--they had no gate attractions--King came to help.

She was back. One more time. One last time?

"If I was realistic, I'd be sitting at home. But, you know, probably when you need the most support from people, you get the least. I had to do something on my own. I couldn't get my wheelchair or my rocking chair out. I had nothing to lose."

In Detroit, she walked off court in mid-match. She said a friend had been shot. She couldn't play on. She was sorry. Someone this week asked about the incident, and she said, "I wasn't happy with myself that day."

And now? "I'm happier with myself. Every day I hold my breath when I say that."

She pursed her lips tightly against the words.

"Every day's a new day," she said.

Every day is match point. She beat 23-year-old Tanya Harford in an early match here. During a press conference, Harford was asked who she had been looking at in the bleachers.

"My young boy friend," she said. "Some of us have them, you know."

JoAnne Russell, another player, sidestepped a question about the players' respect for King. "Are you talking about her personality or her game? . . . There's a difference between respecting someone as a person and respecting their game. I'm sure everyone respects her game. It's just an individual thing. To each his own."

"Billie Jean has a complex," said Pam Shriver, the world's No. 7 player. "If she loses to somebody she shouldn't lose to, she wants everybody to know that that's not really her, or what she was at 26, 27, 28 . . . I wish she wouldn't have a complex. I mean, we were 3 or 4 years old when she was doing her stuff. I think she resents the young kids."

How, King asked, could the young kids appreciate her? "They don't read history books. They weren't there. Most of them don't have no idea because all they see is what they see now and they probably think, 'How in the heck did she ever win?' "

Shriver believes that sense of resentment, whether the resentment is real or imagined, is what drives King.

"She wants to prove to everybody that she still has it. I mean, nobody in women's tennis has ever stood the test of time like Billie Jean . . . The semifinals of Wimbledon at 38! That's fantastic."