Though he's a Ravens fan, Robert Patrick Griffin III of Pasadena, Md., lets his 6-month-old son, Brayden, wear a Redskins jersey -- mostly because it bears the name he shares with the quarterback, the more famous RG3. (Doug Kapustin/For The Washington Post)

If you need to find Robert Griffin III on Sunday, look no further than FedEx Field. He’ll be in the stands, wearing a Baltimore Ravens jersey, rooting loudly against Robert Griffin III’s Redskins.

“Huge rivalry game; I’m not missing this one,” the other RG3 was vowing the other day. “I’m a diehard Ravens fan.”

So from one RG3 to another, much more famous one: Booooo?

No, said the Baltimore-born, 24-year-old, heating-and-air-conditioning-unit-installing Robert Patrick Griffin III. “I love the Ravens; that’s my team. But that RG3, he’s hard not to like, I’ll tell you that.”

Robert Lee Griffin III, the Redskins’ rookie quarterback, is an NFL supernova. The 22-year-old with the incandescent personality and jaw-dropping game leads the league in jersey sales and the Redskins in popular acclaim.

There are people driving around with RG3 license plates, and people transforming themselves into RG3 superheroes. A bunch of fans were RG3 for Halloween, including a kid who dressed as “RJew3.”

RG3 this, RG3 that, RG3 ad infinitum: His name and visage are everywhere, because just about everybody seems to love Robert Griffin III.

It’s a pretty fun time, then, to be an RG3 — any RG3. At least seven Robert Griffin IIIs live in the District, Maryland and Virginia, according to voter registration and other public records.There are scores of other Robert Griffins, sans Roman numeral, in the region, too.

“I was at the Golden Corral recently and there was a couple of guys talking about the Redskins and Robert Griffin, and I said: ‘I’m the real Robert Griffin,’” said Robert Talbot Griffin, a white 72-year-old retired newspaperman from Baltimore.

“I showed those guys my driver’s license, and they got a charge out of that,” RGI recalled. “There’s obviously no connection, but people call RG3 my grandson.”

His “grandson” won the Heisman Trophy in college. He was the second player selected in the 2012 NFL Draft. He currently has the second-highest passer rating in the NFL. He has produced more fantasy football points than any other NFL player this season. He is a human highlight reel of uncommon talent.

He is not uncommonly named, though. In fact, at Baylor University, his teammates included Robert Torrez Griffin, an offensive lineman who wound up being drafted by the New York Jets, 201 spots behind RG3.

Using 1990 Census data — the most recent survey for which both first and last name frequencies were published — Leonard A. Stefanski, a statistics professor at North Carolina State University, calculates that .00264 percent of U.S. males have the name “Robert Griffin.”

That’s approximately two or three Robert Griffins for every 100.000 men, said Stefanski, who crunched the numbers for the Post on behalf of the American Statistical Association. By comparison, Stefanski said, there are about 12 to 13 times as many James Smiths as Robert Griffins.

It’s unclear how many RG3s there might be out there, throwing deep down the sidelines of life. But here’s another one: Robert Lewis Griffin III, a 70-year-old insurance agency owner in Midlothian, southwest of Richmond.

“I was RG3 long before he was RG3,” he said. “We even have the same middle initial — L.”

He has yet to benefit from his namesake’s ascension, though. Nobody has bought him a meal simply because he’s RG3. He hasn’t had a traffic ticket waved off, as Nicanor Obama did in the District four years ago, shortly after Barack Obama was voted into the White House. Nobody is giving him free tickets to see the Redskins, the team he’s followed for years.

And nobody has accidentally mixed up his finances with the football player’s, either. RG3 the QB signed a four-year, $21 million contract with the Redskins and is earning millions more in endorsements.

“I could definitely handle his paycheck,” Robert Lewis Griffin III said. “That would work.”

ESPN played with the idea of celebrity athlete namesakes this year, making a commercial about how the world responds to a Michael Jordan who’s not the Michael Jordan. The reaction is abject disappointment.

Telecom executive Rob Griffen got a little taste of that recently after making a reservation at a Washington restaurant. His name sounds the same, but . . .

“They looked very disappointed when we arrived,” he said.

“I’m not sure the star has rubbed off on him yet,” said his wife, Laura.

Robert Walter Griffin III, a manager at the Wegman’s in Columbia, gets chuckles more than anything. Like the time he was in the checkout line at Lowe’s, and they asked to see his driver’s license.

“They see my full name, and they ask if I’m any relation,” said Griffin, 39. Now he chuckles. “I look absolutely nothing like him. I’m Caucasian, with short hair, and he would absolutely tower over me.”

There is this, though: “I’m a long-distance runner. He’d beat me in a 40-yard dash, but I might be able to take RG3 in a half-marathon.”

But first the quarterback has to finish his rookie season. Sunday’s game against the Ravens is big for the RG3s. One is trying to lead his team to the playoffs. Another — Robert Patrick Griffin III, the 24-year-old air-conditioning installer who’s going to the game in his new black Ravens jersey — wants to avoid being harassed at home.

He lives in Pasadena, in Anne Arundel County, with his girlfriend and her family. They’re all Redskins fans. Even his 6-month-old son, Brayden Patrick Griffin, has a burgundy-and-gold RG3 shirt.

“Everybody in that house loves the Redskins, except me,” he said. “If the Ravens lose, I’m going to have a whole week of earful about it. It’s going to be a week of shame.”

At least there would be this, he said: “I’ll see my name all over TV. That’s always cool.”

Well, not always, said Daniel Snyder.

Not the fabulously wealthy 47-year-old Redskins owner, but the 33-year-old information technology administrator at a Washington consulting firm.

He was in college when Snyder bought the team. It was great, at first — especially the time he made a reservation at Smith & Wollensky steakhouse downtown. “I was taking my future wife to meet my family, and they gave us the [chef’s] table in the kitchen,” he said. “We enjoyed it. The restaurant wasn’t so happy.”

But things changed. The Redskins struggled, and fans lashed out at the owner. His popularity eroded. His namesake, the IT guy, was bereft. “I only had a few years to enjoy it,” he said.

Things will be different with RG3, though, who is “going to be really good for a while,” he predicts. The rookie will be so good, for so long, that he will even help improve Daniel Snyder’s name around town. All boats rise. Of this, Daniel Snyder is certain.

Researcher Jennifer Jenkins also contributed to this story.