Among the world's top gymnasts, the difference between a scintillating 9.4 performance and the once-elusive perfect 10 is largely a matter of risk and originality; technical perfection is taken for granted. In the case of UCLA senior Peter Vidmar, that presumption couldn't be safer. The top-ranking American in world-class competition, Vidmar, 21, captured the prestigious America Cup last month with a performance that beggared superlatives. In six grueling events—pommel horse, rings, high bar, vault, parallel bars, floor exercise—the 5'5", 130-pound bundle of muscle scored 59 of a possible 60 points, more than any U.S. gymnast before him in that competition.

None of this is lost on the Soviet Union, which, along with China, is the dominant power in international men's gymnastics. Last year the Soviets fielded a team of second-stringers for a competition against the up-and-coming Americans, and wound up with egg on their faces. This week, planning to avenge that loss at a dual meet in Los Angeles, they are expected to show up with their A team. Vidmar isn't intimidated, but he believes he and his teammates fell behind their international rivals as a result of the 1980 Olympic boycott. "We had no idea what tricks were being done then in Moscow," he says. "We got passed up. Whatever happens, this meet will be educational and work to our benefit."

For Vidmar, it will also mark another big step toward a gold medal bid at the 1984 Olympic Games in L.A. A highly disciplined Mormon, he works out more than four hours a day, sometimes spending an hour on a single maneuver. "Training is an obsession," he says. "A lot of gymnasts go through the same workouts every day, but the ones who can put out that little extra are the ones who rise." His trainer, UCLA assistant coach Makoto Sakamoto, recalls a time when Peter spent four slavish years struggling to master a difficult stunt. "Peter is not particularly talented," he says. "I've had boys who were more gifted physically, with more kinetic awareness, strength and flexibility. But Peter could surpass them all because of his singular determination and motivation."

One of six children of a Borg Warner Division senior vice-president, Peter grew up in L.A. loving sports, but found himself frustrated because of his size. "It was hard to be an asset to a team," he says. "I was more like a liability." At 11, he discovered gymnastics at the Sakamoto brothers' Culver City gym, and was later inspired by the Olympic heroics of Olga Korbut and Nadia Comaneci. "I daydreamed a lot in school back then," he recalls, "so I tried to put that into action."

Despite missing almost a third of his college classes due to gymnastics, Vidmar has majored in economics and maintained a respectable B-minus average. He and his fiancée, former UCLA gymnast Donna Harris, plan to marry this summer, then cram in a three-day honeymoon between meets. "There's not much time," explains Peter. "It's hard to do things on a whim."

Despite the incessant demands of training and competition, Vidmar is a fun-loving sort who is decidedly not all work and no play. Yet he has good reason to take his practice time seriously. His freshman-year roommate, Mark Caso, barely escaped being permanently paralyzed by a twisting dive-and-roll floor stunt when he soared seven feet in the air, lost his bearings and fell, breaking his neck. Donna herself left the sport after recurring wrist problems. Vidmar has never been hurt, but realizes that pushing himself toward a gymnastics world championship will require mastering increasingly treacherous stunts. He is determined not to let that stand in his way. "There's always fear," Peter says calmly. "The trick is not to eliminate it, but to overcome it. When you try a new trick, go for it. It's when you hold back that you get into trouble."