It took John Schneider almost six months into the league year to do it, but he pulled off the big bang we thought he would.

Every odd year since 2011, he has made a stunning signing or trade — and he obviously is hoping Sheldon Richardson turns out more like Jimmy Graham than Percy Harvin or Sidney Rice. Even if it’s for only one year.

The deal that sent Jermaine Kearse, a 2018 second-round pick and a seventh-rounder to the New York Jets for Richardson and a seventh is Seattle’s Big Bang Theory: Add a Young Sheldon and create a universe in which Seattle’s defense goes where no defense has gone before.

For one year anyway. This is almost surely just a one-year rental. And it works best that way.

Richardson has become known as a great player with a bad attitude and questionable off-field judgment — he’s on probation for reckless driving/resisting arrest and also is in the NFL’s drug program after serving a four-game suspension in 2015, reportedly for a positive marijuana test.

But the attitude might simply have been the product of a toxic, losing environment in New York. And the poor judgment hopefully was just immaturity. It’s a minor gamble, but Seattle’s defensive leaders — Mike Bennett, Cliff Avril, Kam Chancellor, et al. — will hold him accountable. And, since he is playing for a new contract, they should get his best at age 26.

“Another team wanted me,” Richardson told ESPN’s Josina Anderson. “Got to roll with the punches. I’m happy for the situation I’m in now. Fresh start.

“I want to get out there and start on defense,” he said. “That’s the plan.”

But he said the Seahawks did not guarantee he will start. He’ll probably begin in a Jet City turbo nickel rush with Bennett, Avril and Frank Clark. That trio combined for 26.5 sacks, leading the league’s No. 3 pass rush in 2016.

Richardson has 18 sacks in his first four years, including eight in his 2014 Pro Bowl season. And he was highly ranked as a run defender while playing out of position a lot the past two years under Jets coach Todd Bowles.

Bottom line: Richardson gives the Hawks an amazing two-way talent who should make Bennett, Avril, Clark and Seattle’s elite defense even more legendary.

The Seahawks apparently first started talking to the Jets about Richardson around the draft. Their No. 2 priority this offseason — behind upgrading the offensive line — was to get a 3-technique who could provide the interior rush they have not consistently had since they won the Super Bowl in 2013 (Richardson’s rookie season).

They apparently lowballed the Jets and Richardson on the first pass — he declined a pay cut, saying, “It’s a business, bro.” So the Hawks picked Malik McDowell in the second round and hoped they had found their interior rusher. But then they lost him to the ATV accident — possibly forever.

After seeing what they had — or didn’t have — in preseason, they resumed talks with the Jets (who reportedly turned down the same offer a week ago). The Hawks were able to accommodate Richardson’s $8.1 million salary (off his rookie option) because Doug Baldwin restructured his deal to clear $5.2 million in space and they divested Kearse’s $2.2 million salary in the trade.

Baldwin gets the Team Player Award for the year: He helped the Seahawks trade his friend Kearse, knowing it would give Seattle an even better chance at winning another Super Bowl.

Assuming he plays to his standards, Richardson is expected to get more than twice his 2017 salary in a new deal next year. The Hawks, of course, will not be able to afford $18 million a year. Instead, they surely will let him go and be happy to take the third-round comp pick in 2019, which will mostly offset the 2018 second-rounder.

And, if this Big Bang Theory works and the Seahawks do rule the universe in 2017, Young Sheldon will take a Super Bowl ring with him when he spins off to another team.