Semi-Tough is written in the form of a journal or diary that Billy Clyde has been commissioned to keep as a record of the team's preparation for the Super Bowl. In fact, it is a highly personal, impressionistic book of days interspersed with memories of Billy Clyde's past. The tension between what the journal is supposed to accomplish and what it actually does is a comment upon the sports world that Billy Clyde inhabits. His preparation for the big game consists of nonstop parties, lots of sex and laughs, and sheer good times.

There is not a tightly-structured plot; the novel is episodic, anecdotal. There are two central actions which function as unifying elements: the Super Bowl game and the ultimate declaration of love between Billy Clyde and Barbara Jane Bookman. The novel, in the tradition of comedy, ends with the promise of a marriage.