Colleagues describe Mr. Nondorf as a “super-marketer,” a man who gets results. At Yale, he helped diversify the applicant pool and pioneered the university’s use of a “likely letter,” sent to top applicants before official acceptances. In three years as the top enrollment official at Rensselaer Polytechnic Institute, he oversaw a doubling of applications, which brought record numbers of women.

At Chicago, Mr. Nondorf’s first priority was to create a recruitment booklet that contained many photographs of students engaged in group activities, including music, dance, tennis and football. Later, Chicago sent tailored letters to students who had expressed an interest in the arts or in medicine. Admissions officers talked up pre-professional opportunities and career preparation. Visiting families received special rates from the Hilton, where a letter from Mr. Nondorf and a pouch of chocolates awaited them. Over the last year, Chicago’s admissions representatives visited about twice as many high schools as they had the previous year. Mr. Nondorf sent three to California instead of one, and for the first time, the university received more applications from the Golden State than from Illinois.

Chicago officials have cited many reasons for this year’s application explosion, including the popularity of President Obama, who taught at the university. But some credit should go to Royall & Company, a direct-marketing firm hired last spring to help conduct an expansive recruitment campaign. This included a series of short e-mails sent in rapid succession; some students received nearly 20 in all. This year, Royall’s clients averaged a 7 percent increase in applicants.

To each applicant, Chicago assigns a “fit” rating based on holistic measures — say, intellectual curiosity or evidence that a student applied a favorite subject to life. This year it admitted more top students with high ratings than in the past, according to Mr. Nondorf. “The number of applications reflects something, but they’re not necessarily what we’re after,” he says. “Crafting a better educational experience through a better class is the goal.”

Still, at an admissions conference in Rhode Island this May, Mr. Nondorf described the pressure on deans. “Don’t kid yourselves, the presidents and trustees want you to have more applications,” he said. “If you don’t think that’s the case, I don’t know what schools you’re working at, but it’s true.”

Mr. Boyer has compared Chicago’s application total with that of Columbia University, which also has a strong liberal arts curriculum. “I believe we are a better university than they are, so I think we should have more applications than they do,” he told the student newspaper last winter. The remark was a “friendly, competitive gesture,” Mr. Boyer says today. “I don’t think Chicago should stand behind New York on this one. We deserve the same number of applications, if not more.”

Such talk worries Andre Phillips, who left Chicago last year after two decades as associate director of admissions. “By changing the admissions culture, Chicago has gone in for the quick fix,” he says. “My concern is that the institution is marketing itself as something it isn’t.”