Success, failure, and life's stresses through a soccer goalie's eyes; The Boy's Own Story Play by Peter Flannery. Starring Jim Piddock. Directed by Richard Seyd.

Jim Piddock, the engagingly nimble manservant of the recent splendid revival of Noel Coward's ''Present Laughter,'' has forsaken the drawing room for the playing field. Instead of facilitating sophisticated indoor sports, Mr. Piddock is educating York Theater playgoers in the physical rigors and soul-testing ordeals of British soccer.

''The Boy's Own Story,'' by Peter Flannery, casts Mr. Piddock as John McKenna , a once-famous goalkeeper. In the course of an anticlimactic final match, McKenna looks back on his bleak life, short-lived triumphs, and traumatic descent from glory.

If Mr. Flannery is to be believed, the goalie's lot is not merely unhappy but peculiarly isolated. McKenna's case is aggravated by the fact that he has always been a loner. As a small orphan boy, he was bullied into keeping goal by a trio of neighborhood bullies. In subsequent practice against a brick wall, he polished his skills, discovering meanwhile the vocation that became his obsession and eventually his undoing.

Mr. Piddock literally hurls himself into his role as McKenna makes the spectacular flying leaps that represent saves and that made his reputation. The actor is equally adept at conveying the psychological tensions, the frustrations and bitterness, the comic and mordant ironies, and specifically the problems of a compulsive introvert engaged in an extrovert sport.

Along with autobiography, McKenna offers some incidental instruction about the techniques and finer points of goalkeeping. He became so famous for his saves that what the public wanted to see was how long he could go without conceding a goal. But his very virtuosity - plus his antisocial behavior with teammates off the field - became his undoing. Four weeks after a Wembley cup final he was sent to the reserves.

''The Boy's Own Story'' is also concerned with the philosophical and often personally damaging aspects of competition as epitomized by professional sports: the ambivalence as well as the pressure of success and the fear of failure. As McKenna observes, a 0-to-0 tie game means that the goalkeeper has succeeded but his teammates have failed. At one point, he remarks ruefully: ''Even the poorest goals go into the record books, but the greatest save is forgotten.''

Periodically McKenna interrupts his recital to exhort or berate the mediocre team of provincial semi-pros of which he is player-coach. Whether in restless motion or reflective repose, Mr. Piddock achieves the objective in a one-man play of not only representing the protagonist but of suggesting the world around him (occasionally in vignettes of other characters). Thus he explores the varied possibilities of a brilliant work that is part sports documentary, part social-satirical comment, and part psychological study.

The production sharply staged by Richard Seyd accordingly succeeds on both its specific and more general terms. In James Morgan's scenic design, the goalkeeper's cage beyond a patch of greensward (brightly lighted by Molly Grose) provides symbol and metaphor for an incisive drama about a self-made success-failure trapped in a destiny partly of his own making and partly the result of outside pressures and circumstances.