DALLAS -- The world's best female athlete sees her toughest challenger daily. She just looks in the mirror.

Jackie Joyner-Kersee isn't impressed. And that's why she is so impressive; she just keeps pushing.

"I believe that God gave us all different talents and that it's left up to us to develop to the best possible level," she said. "If you don't believe in yourself, you destroy your life."

Joyner-Kersee, the most gifted woman athlete since Babe Didriksen-Zaharias, next weekend launches what could be her greatest year yet in track and field. She's competing in only one event, the long jump, which she won at 22-feet-8 1/2 inches at the Panasonic Millrose Games in New York on Friday night; and she was set to compete in The Dallas Morning News Indoor Games last night -- which all seems rather modest by her standards. But it is the first step in a long-range plan that husband-coach Bob Kersee has for her in this Olympic year.

She will try for the same dramatic improvement jumping indoors as she achieved outdoors last year, then work toward major performances outdoors in the long jump and heptathlon. Her major checkpoint will be the U.S. Olympic Trials in Indianapolis on July 15-23, her final destination being the Olympic Games in Seoul, South Korea, on Sept. 23-Oct. 2.

Through it all, Joyner-Kersee won't lack for stimulation. Her husband, the driving force of the World Class Track Club in Long Beach, Calif., will guide and chide her, and she won't be easy on herself. She thrives on pressure.

Once you chart this superstar for a while, you realize she is extremely competitive -- with herself. That's why her best may be yet to come.

She had that tremendous year in 1986, twice breaking the world record for the heptathlon, but she came back last year determined to reach another goal. The result: a world-record-tying long jump of 24 feet 5 1/2 inches at the Pan American Games, then a triumphant summit meeting with East Germany's Heike Drechsler at the World Track and Field Championships in Rome.

It was a surprisingly easy victory for Joyner-Kersee and came three days after she won the heptathlon title by scoring 7,128 points in the two-day, seven-event competition. It was satisfying, but not the ultimate. Now comes the opportunity to win the Olympic gold medal she barely missed in the heptathlon at the '84 Games in Los Angeles.

In the heptathlon, Joyner-Kersee has the four highest scores in history including 7,158 and 7,148 in '86. Kersee feels Seoul can be the ideal showcase for her greatest performance yet.

"My goal is to see her break the world record in the heptathlon in the Olympic Games," Kersee said. "I've always watched the great decathletes in the Olympics. The man who won was called the world's greatest athlete and that excited me. I'd love to see my wife in that position."

Joyner-Kersee hopes her experience of winning the long jump under great pressure at Rome will serve her well in the Olympics.

"I hadn't beaten Heike Drechsler before but most important was having a good performance on the world stage," she said. "Blocking everything out and doing it was more important than being on the gold medal stand."

But people who have been close to her for years saw her there, flashing her wide, easy smile, and felt a special pride.

"I think the world of my sister," said Al Joyner, himself a gold medal winner, "and I'm not talking about a great athlete but a great person."

Billie Moore, the UCLA women's basketball coach and 1976 Olympic coach, who recruited Jackie from East St. Louis, Ill., puts her in a class by herself.

"If I coached another 40 years, I don't think I could find someone else like Jackie," Moore said. "She's a winner and a competitor. She knows how to prepare and what it takes to win. . .

"At UCLA, Jackie competed in basketball and track and it was a happy marriage between the two sports. But if she had specialized in basketball, she would have made the Olympic team. Same thing in volleyball. But as great an athlete as she is, she's an even greater human being."

Moore is delighted to have Jackie involved in UCLA basketball again as an assistant coach on a modified basis. Jackie finds it rewarding, too.

"Track is my main thing but this gives me another dimension, adds to me as a person," she said. "It makes me feel good that these young women listen. They want to be better athletes and better people."

To Joyner-Kersee, that's what life is all about. It's a legacy from her mother, Mary Joyner, who died from spinal meningitis at age 36 when Jackie was a UCLA freshman.

"I've always tried to move forward, and a lot of that came from my mother," Joyner-Kersee said. "She got pregnant at age 14 and she couldn't get a lot of things she wanted in life because she had a family. She didn't want us to take the route she took.

"When I got the scholarship to UCLA, I knew if I could come to a school like that and make it, nothing could hold me back."