Redskins have many options for quarterback Kirk Cousins. (Jonathan Newton/The Washington Post)

Now that the NFL’s window for applying the franchise tag is here, opinions are flying about what the Redskins should do with quarterback Kirk Cousins:

Keep the quarterback under wraps by using the costly franchise tag for a second consecutive year?

Tag him, but ultimately broker a long-term contract?

Tag and trade him, to get value for Cousins, whose stock is high, and take their chances with veteran backup Colt McCoy or 23-year-old Nate Sudfeld, a sixth-round pick in 2016, or woo an established free agent.

Former NFL coach Steve Mariucci, who was Brett Favre’s quarterback coach at Green Bay before being named head coach in San Francisco and, later, Detroit, has a unique way of analyzing the pros and cons.

It starts with an eye-popping number: 7.3 billion. And it leads to this conclusion: “You’ve got to keep [Cousins], and you’re gonna have to pay him and keep your fingers crossed that you can still surround him with enough supporting cast to get it done.”

Here’s how Mariucci, now an NFL Network analyst, sized it up in a recent interview.
“There are 7.3 billion people on this planet, last I counted,” Mariucci said. “But there are not enough human beings to fill the 32 franchise quarterback spots; they don’t exist. So when you have a [Tom] Brady and [Aaron] Rodgers, a Matt Ryan and a [Ben] Roethlisberger — those great, Pro Bowl, franchise kind of guys — you just thank your lucky stars every day.”

Meanwhile, the 28-odd other NFL teams are looking for that caliber-quarterback, and many end up overpaying — awarding $20 million-a-year contracts and up on a hunch.

The questions facing the Redskins, five years after their costly trade to draft Robert Griffin III, who seemed a surefire franchise-quarterback, are these: Do they keep Cousins, who’ll be 29 when the 2017 regular-season opens? Invest in a younger player? Draft a quarterback and start over?

“Not every rookie quarterback is gonna have success like Dak Prescott did, with a great offensive line and all the things he did so well,” Mariucci cautions. “Teams like Houston, they’re gonna have to overpay at quarterback and say, ‘Maybe this is the guy that takes us there.’ There are gonna be some swings and some misses and some successes.”

In the case of the Redskins, Mariucci believes, the smart play is to acknowledge that keeping Cousins is going to be costly — and do it.

“He’s a heck of a player,” says Mariucci, a Michigan native who has followed Cousins’s career since the undersized, under-recruited quarterback from Holland (Mich.) Christian signed with Michigan State. “He wasn’t one of those five-star recruits, then. But he is a class act, a great human being and a heck of a leader. Whether you call him an overachiever or not, I think you sign him, and that’s your guy.”