Passage from “The Chase”: “Nothing girls did could compare w…

Passage from “The Chase”: “Nothing girls did could compare with it. Boys welcomed me at baseball, too, for I had, through enthusiastic practice, what was weirdly known as a boy’s arm. In winter, in the snow, there was neither baseball nor football, so the boys and I threw snowballs at passing cars.”   The reference to possessing “a boy’s arm” reveals: