Most would agree that the season’s biggest Tony winner, “Once,” can now expect to run longer than it would have without those eight awards. But how much longer?

A theater vet might respond: No telling, kid, because Broadway ain’t an exact science. But a statistician would answer: about 50% longer.

That’s according to a new study recently completed by a trio of academics. The report, an update of an initial survey of the three seasons from 1996-97 through 1998-99, looked at newer data from open-ended shows in a window stretching from 2000-01 through 2008-09.

Legiters will snicker at the futility of finding a formula for showbiz, and even New York U. professor Jeffrey Simonoff, one of the researchers who undertook the project, admits there are few surprises (and even fewer for industry types) in the study.

But the findings represent a first step, he argues, toward more detailed research that could help producers become better at diagnosing what’s ailing a show at the box office, and understanding how to fix it.

Simonoff and colleagues Lan Ma Nygren (a faculty member at Rider U.) and Nikolay Kulmatitskiy (a Ph.D. student at NYU) looked at Tony wins in what they considered “major categories” — musical, tuner revival, play, play revival, director and lead actor and actress. Sure enough, they found that each Tony in one of those categories is associated with a 50% longer expected run, while a nom without the win was associated with a 30% longer expected lifespan.

Of course, any math is muddied by the possible reading that the Tony noms and awards are markers of aesthetic quality (insert any skepticism here), so it’s only natural for nominations-magnets to draw more crowds and have more legs.

And a lot of the study’s findings confirm what people in the business know already: Everybody’s pretty clear, for instance, on the fact that musicals run longer than plays (about 40% longer, for the majority of a season’s shows). And it’s well established that successful tuner revivals generally have less life in them than new hit musicals (about 20% less life for that same majority).

Perhaps the most unexpected finding was the study’s assertion that, for shows that opened between June and February, a positive review in the New York Daily News often corresponded to a longer expected run, whereas a thumbs-up in the New York Times was associated with a shorter expected run.

Legiters will likely argue about that one, particularly on a show-by-show basis. But the idea that tourist ticketbuyers are paying less and less attention to newspaper reviews in general won’t meet much resistance these days.

The fact that the initial findings correspond to the industry’s widely held understanding of the biz could be a favorable indicator that more detailed research might yield deeper observations that could prove surprising but no less accurate.

As Simonoff puts it: “If you can think quantitatively, you can do better than if you only think qualitatively.”