For Melanie Smith, show jumping is not merely a sport, it's a way of life. At 33, almost a lifetime of horse schooling, training and riding has finally paid off. Smith is now considered the world's best show jumper.

This spring, Smith and her favorite horse, Calypso, a 9-year-old bay gelding, captured the World Cup Championship in Goteborg, Sweden. Smith had beaten the world's best riders on their own turf and she received the cheers and applause of the crowd of 12,000 that jammed the arena. The United States ambassador phoned his congratulations.

"It was the most exciting win of my career," Smith said.

Smith, who is representing the U.S. in jumping competition against representatives of France, Switzerland and Canada at Capital Centre, cherishes her role.

"It's an honor to be on the team, to represent this country. Washington is a top show and the international teams make it even more thrilling," she said. "It's even more exciting when you hear the national anthem played out of the country. It makes me proud. I get chills down my back."

Smith was reared on her parents' farm in Germantown, Tenn., where her mother operated a riding school. Because of the childhood riding experience, she's never nervous when she's showing a horse. Occasionally, she "just gets excited."

Smith, who now lives in Litchfield, Conn., is the first rider to win the triple crown of show jumping -- the American Jumping Derby in Newport, R.I., the American Gold Cup in Philadelphia and the American Invitational in Tampa this year. In fact, although she spent most of the summer competing in Europe and away from the American Grand Prix circuit, she is in fourth place for rider-of-the-year honors after winning the speed stakes on Grand Siecle at the Baltimore International Classic earlier this month.

The next Grand Prix event is the $35,000 President's Cup, Sunday night's feature at the Washington show. Smith won aboard Calypso last year, when she finished third in the race for rider of the year.

Ten years ago, Smith achieved her first major victory when she rode Chapo in the international-open jumper class. Monday night, Smith rode Calypso in the same class, beating an original field of 33 to again win the $5,000 Dwight D. Eisenhower Memorial Perpetual Trophy. She didn't cry this time but "the thrill is never gone. It's always nice to win here at Washington because they have such big beautiful trophies."

Smith is also a popular competitor. In a span of about 10 minutes, she was greeted by nearly a dozen riders, grooms, horse owners and fans who brought her up to date on the horse-circuit news. She missed last week's show in Harrisburg, Pa., because "I wanted my horses to be fresh for this show and for New York," referring to the National Horse Show next week in Madison Square Garden.

Competing in a sport that badly needs recognizable personalities to promote itself in America, Smith says she could possibly see herself as a Chris Evert or Jimmy Connors of show jumping. "The sport needs personalities. I want to help in any way I can; not for me but for the sport."

The cover of the horse show program carries a color photograph of Smith on Calypso, the first such picture in horse show history.

Marc St. James, who heads the partnership that owns Calypso and who sponsors Smith through his Windrush Farms in Connecticut, felt show jumping needed some outside help. In September, a New York public relations firm was hired to promote Smith.

Smith's longtime teacher, George Morris, says his student "is in a class by herself. She's a natural horsewoman and a great competitor."

Not only is she "a good rider, but she's also intelligent. She uses her head while riding," said Rodney Jenkins, show jumping's best known American rider before Smith. "She has a good horse and they work well together."

Morris goes a step farther. "She and that horse (Calypso) are the strongest combination in America. She makes him a beautiful horse; she's nice to him, so he'll do anything for her."