"I don't know quite why you're writing this," she mutters at the beginning of the interview, a picture of modesty as she blushes slightly, smiles sweetly, and opens her large blue eyes astonished that anybody could be interested in her exploits on the soccer field.

Perhaps she has a point. What has Julie Brynteson done of note this year? Isn't she just another pretty face? Judge for yourself. She's co-captain of the women's soccer team. She's tallied eight goals and seven assists in just 11 games, a pace that Guy Lafleur, if not Sue St. Louis, would be envious of. She banged home all three goals in the Crimson's 3-0 shutout of Brown Saturday that made Harvard the first official Ivy League women's soccer champs. And she then carted home the Ivy league tournament MVP award from Providence.

She didn't accomplish all that by smiling sweetly at the other team. In fact, the Brynteson that sprints up and down the wings, booms crosses and corner kicks in front of the opposing team's goalposts, steals the ball from defenders with crushing tackles and mumbles occasional expletives under her breath during games, is a far fiercer creature than the Bryntson that confronts the reporter on the sideline.

The transformation from the unassuming, spotlight side-stepping Brvnteson one sees between games, to the intensely competitive player one sees on the fields, is not something that comes with the imbibing of a little locker room elixir, a-la Jeckyll and Hyde. The hardnosed Brynteson is the character that has emerged during the last three years during her late-in-life apprenticeship in competitive sports.

Before coming to Harvard, Brynteson had not participated in any competitive athletics; except an occasional football game with her elder brothers. That, however, does not mean she came to Harvard as a stranger to soccer.

She had her first meeting with soccer during her high school years in St. Paul, Minnesota; that meeting, as manager of the boy's varsity for three years, was to be the beginning of a long and beautiful friendship.

Absorbing the tactics and strategy of soccer, if not the skills, (she was inhibited from trying to play herself because "the others were all so good")--Brynteson came to Harvard ready to plug in to a still fledgling women's program in 1976. Thanks to the likes of her, that program soon learned to fly and after last year's 9-2-1 record and her election as co-captain Brynteson returned home for a summer of preparation for the 1979 season.

Taking advantage of the phenomenally quick growth of soccer in this country, Brynteson joined two women's leagues this summer, both of which were in their first year. She impressed one of her male coaches so much that he invited her to spend August coaching kids of both sexes between the ages of eight and 18 at a camp he directed. She admits that "at first the older boys laughed," then adds, allowing a glimpse of the inner self-confidence beneath the humble exterior, "until they'd seen me play."

Brynteson also spent hours this summer kicking a ball against a wall to strengthen her kick, and ignoring the cries of passing hecklers who would inform her that "de ball ain't gonna go through no matter how many times you kick it."

Her summer of hard work payed off. As coach Bob Scalise said yesterday, "She's improved. She's now a very skillful player who has the ability to take people on one-on-one. She also has a very strong kick, and a very powerful shot."

As a co-captain, her leadership has been no less important; "She comes early and stays late at practice. She's helped our new people feel more at ease, setting up drills with them and doing other such things," Scalise said. Along with the other co-captain Paula Levihn, she's helped mould what Scalise calls "a very cohesive team."

Julie herself admits that the team's cohesiveness, in addition to their superior fitness which helps them outrun most other teams, and their coaching, has been a vital factor in the team's phenomenal 11-0 success. Naturally she takes no credit for that cohesiveness, emphasizing that it derives from the dedication of each individual member of the team.

But even if she, humble as ever, could only repeat at the end of the interview "I still don't know quite why you're writing this," others may now have an inkling of the reason.