G. Gaddis Smith ’54 GRD ’61, the emeritus history professor, likes to tell a story.

It was September 1951 for the Pierson College student, the start of his sophomore year. He had returned from the summer not with a Miami tan but with a spouse: Smith had married a woman named Barclay, his wife to this day, just weeks before.

That, according to the tale, is when he was summoned by the associate dean of Yale College, Richard Carroll, for violating the rules of Yale College: “Do you realize,” the dean prodded Smith half-jokingly, “what would happen to the residential-college system if everyone got married?”

If Smith, who did not live in Pierson College until he became its master years later, is any indication, then lots of students would move off campus, especially seniors. The intimacy they would come to feel toward their spouses could replace that which they at one time felt toward their college.

In 2008, youth are marrying later in life. But the residential-college system is nonetheless inching toward the scenario Carroll feared. In 1965, 96.4 percent of undergraduates lived in their residential colleges. In 2007, that figure had dropped to 87.1 percent — a marked increase from the abysmally low numbers of the early 1990s, before administrators mandated that freshmen and sophomores live on campus, but still not quite what it could be.

Tumbleweed will never be found loafing across the courtyards, and the alarm need not sound on Harkness Tower anytime soon. Residential-college life thrives today through energetic masters and deans, college councils, intramural rivalries, butteries and the intrinsic pride that comes with the territory.

But times have changed. Gates between rival colleges have been unlocked. Bladderball has been virtually forgotten. The Tyng Cup, for some, has lost its shine.

Residential-college life, simply put but begrudgingly admitted, is not what it once was for many students. Some of us bleed Branford blue and bathe in Trumbull burgundy, but for some Elis, the umbilical cord that should connect student to college is hanging by a thread — an occasional dance here, a dash to the dining hall there.

At some point, we must stop to ask ourselves why the students who move off campus do so. For years, root rationale has included affiliation with a group — an athletic team or an a cappella group — or plain economics: Living in an apartment or a house is often less expensive than living on campus (and being forced to pay for board). And housing shortages have perhaps contributed above all.

The report released in February of the Study Group to Consider New Residential Colleges set a goal of injecting the residential system with new life, mainly by reducing overcrowding and lessening inequalities between colleges. “Housing presents perhaps the clearest opportunity to make changes that will enhance the vitality and effectiveness of the colleges,” the report said.

But that captures only part of the equation. More important, we think, are efforts that can start now to truly engage students in residential-college life so as to overcome the pull of living off campus for those on the edge: a symposium, perhaps as soon as April, that brings together all 12 masters and both “involved” and uninvolved students to answer a plain but pressing question. How can residential-college life regain its sparkle — for all students? (The unmarried ones, at least.)

To kick off the brainstorm, we have some modest ideas: a resurrection of bladderball; campuswide Quidditch; intramural competitions on Old Campus or Cross Campus; late-night dining hall hours; the introduction of kitchens; a themed dance every third Friday; more outlets to express inter-college rivalry. This list could go on for pages.

But who are we, locked in 202 York St. half the day and most of the night, to ask?

Consult the archives instead: The residential college of tomorrow should, and can, reflect the glory of the residential college of yesterday, save, that is, for the homogeneity, the locked gates — and, we hope, the threats of expulsion.