The practice of reserving spots for athletes in minor sports has grown in recent years, people involved with college sports say, as more colleges have committed to pursuing excellence in every activity, from the chemistry lab to the tennis courts. Also, as the population continues to grow, slots at the most selective colleges are more competitive than ever.

Stanford University said that last year, 47,450 students applied for admission, and the university accepted just 2,040. The acceptance rate of 4.29 percent was the lowest in Stanford’s history. No wonder, according to the complaint, the prominent Massachusetts real estate developer John B. Wilson paid hundreds of thousands of dollars in 2018 to secure a spot for his daughter at Stanford.

Federal prosecutors did not charge students or universities with wrongdoing.

At the heart of the scheme was William Singer, who, between 2011 and 2018, collected $25 million from parents to bribe coaches, and encouraged them to go to great lengths to falsely present their children as the sort of top-flight athletes that coaches would want to recruit.

According to the indictment, Singer fabricated athletic “profiles” of the students to submit with their applications, which contained teams the students had not played on and fake honors not won. One student sat on a rowing machine to pass herself off as a rower. Singer’s associates also photoshopped the faces of the applicants onto images of athletes found on the internet.

Kathy DeBoer, the executive director of the American Volleyball Coaches Association, said “people in the volleyball community know who the elite athletes are, but there isn’t enough of a spectator base at most places.”

Even fans of extraordinarily popular volleyball squads, like Nebraska’s, “are following who they’re bringing in,” she said, “but they may not be following their walk-ons. And there isn’t a community that is vested in who are the preferred walk-ons coming on to the volleyball team.”