The sports world cleared a major social hurdle on Monday when NBA center Jason Collins became the first player in major American sports to reveal he was gay, while still in the league. Collins’ revelation is expected to encourage other athletes to come out.

That got the Foreign Policy to thinking: Where are all the gay military officers?

“There is no equivalent. There’s no Jackie Robinson” for gays in military, said Aaron Belkin, executive director of the Palm Center, a California-based research institute and key figure behind the repeal of the military’s “don’t ask, don’t tell” policy in 2011.

So why not?

“There are a lot of people out there, and a lot of those people have come out. But the thing is that because they are military officers and not NBA stars, they came out quietly,” he said, “and very often they don’t even come out to all members of their units.

“We weren’t expecting heroes to step out and become famous. We were expecting business as usual.”

Before the repeal of “don’t ask, don’t tell,” a 2010 UCLA study estimated that 2 percent of troops in the U.S. military likely were gay. That meant at the time that 66,000 people in the military could be gay: 13,000 in the active duty force and 53,000 in the National Guard and reserves. Other estimates emerged, but that was a common ballpark reference.

FP did some math.

There are about 236,000 officers in the military currently. So, based on the 2 percent rate there should be about 4,720 gay officers — more than enough to field a brigade.

By the same math, 1,138,000 enlisted men and women equals about 22,700 gays and lesbians in those ranks.

After keeping close tabs on its openly gay troops for so long under DADT, the Pentagon today doesn’t care much anymore.

“We don’t ask or track the sexual orientation of our service members,” a Pentagon spokesman said this week.

It will require additional independent surveying to determine how many more troops have come out since the repeal. A 2011 survey by OutServe, a leading advocacy group behind the repeal, found that roughly half of self-identifying gay troops said that they had come out to members of their unit after the repeal. Only a third had come out to everyone in their unit.

After about 100 troops came out on the day of the repeal, only Brig. Gen. Tammy Smith, a one-star, did so with public fanfare, as deputy chief of the Army Reserve.

“I think it’s an imperfect metaphor. In sports, you have very few people, and they’re all in the public spotlight,” Belkin said, whereas the opposite is true for the military.

More likely, he argued, Collins’ revelation could mean more to changing attitudes in the wider African-American community than in professional sports, now that blacks have a new gay public role model.

More than 14,000 troops were booted from the service due to “don’t ask, don’t tell” from 1993 to 2001, according to the Defense Department.

Kevin Baron is a columnist for Foreign Policy.