The Dude never actually bowls at any point in the movie
One of the most grounding elements of an otherwise spiraling film of dream sequences, kidnapping, porn, and morose German philosophy are the scenes inside the bowling alley. They bring an earthy, working-class realness to the core protagonists. Oddly enough, however, at no point in the film is the “hero” (of sorts), the Dude, actually shown bowling. The closest we get is the dream sequence when he does a sort of “bowling dance” with a Viking costume-clad Maude, but even then, she is the one that rolls the ball.
Maybe it’s a stylistic thing — a reflection of the Dude’s passive nature. Even in the course of engaging with something he is passionate about, the events still simply happen around him, rather than being shaped at all by his will or action. Maybe Jeff Bridges doesn’t actually know how bowling works?