There is an embarrassing blank where the NFL’s plausible excuse for Josh Brown should be. An excuse does not exist. In place of it there is only clubbiness and deceit. Long before New York Giants kicker Brown was released Tuesday, the league knew all it needed to know about him: He is a spousal abuser.

Commissioner Roger Goodell had the information required to impose a six-game suspension months ago, and simply chose not to, because he’s more concerned with dress code violations and self-interest than domestic violence. It’s as simple as that, no matter what he says.

Goodell will go down as a figure of historical ineptitude. Of this he is blissfully unaware. He failed to get all the facts on Brown and handed him a light one-game suspension for domestic violence, while pursuing Tom Brady for four games over the amount of air in a football. He seems to think anyone who questions these priorities lacks intelligence and fails to discern his subtle brilliance.

“I understand the public’s misunderstanding of those things and how that can be difficult for them to understand, how we get to those positions,” Goodell told a BBC reporter while in London for the Giants game Sunday.

There you have it: The public is stupid.

[The Josh Brown affair shows that the NFL learned nothing from the Ray Rice case]

In fact, Goodell’s “position” is that of a contortionist whose head is stuck in his own smelly underarm. After botching and bumbling his way through the Ray Rice case in 2014, Goodell pronounced himself an enlightened man — as opposed to a callously self-serving, implacably superficial one — and ushered in a tough new policy with baseline six-game penalty for domestic violence.

“Effective immediately violations of the Personal Conduct Policy regarding assault, battery, domestic violence or sexual assault that involve physical force will be subject to a suspension without pay of six games for a first offense,” he announced.

We should have known right then that he didn’t mean a word of it. Look carefully at that statement. What assault, battery, domestic violence or sexual assault doesn’t involve “physical force?” He was leaving himself a loophole.

Goodell’s excuse for why he didn’t act more firmly with Brown is nothing but a shell game, willful misdirection: He claims he didn’t have enough information. “We have asked repeatedly for those facts and . . . we weren’t able to get access to it,” he insisted again in London.

But here are the facts the NFL officials were in possession of more than a year ago. They knew that Brown was arrested for assaulting his wife, Molly, in May 2015. They knew that Brown went after her again at the January 2016 Pro Bowl, drunkenly pounding on her door, until NFL security were called. They knew that Molly Brown and her children had to be moved to a different room for their safety.

[The NFL’s problem with women persists thanks to John Mara and Roger Goodell]

Brown confessed to the New York Giants. “He admitted to us that he’s abused his wife in the past,” team owner John Mara told WFAN on Thursday. Mara then added this stunning qualifier that explains the whole deal. “I think what’s a little unclear is the extent of that.”

So Goodell reduced Brown’s suspension to one game because, maybe, he only roughed her up a little?

Here is another fact: Mara is the chairman of the NFL Management Council Executive Committee. He works more closely with Goodell than any other owner in the league, and his political support is indispensable to the commissioner.

On Tuesday after returning from London, the Giants finally released Brown, who issued a somewhat contradictory statement pledging to get treatment.

But the Brown case will continue to reverberate for what it exposed about the league’s supposed policy. When you line the facts up, what’s clear is just how hard Goodell had to try to be passive. He continues to blame-shift, insisting that uncooperative law enforcement foiled him at every turn.

But really, the league made only a “goofus” effort to investigate Brown’s conduct, according to King County Sheriff John Urquhart. The NFL could have gotten information by placing a forthright phone call to the sheriff’s office. While the sheriff couldn’t release an active case file, “We probably would have told them orally a little bit more about what we had,” Urquhart said. What they had was evidence that Brown was a serial abuser; his wife reported more than 20 disturbing incidents.

Instead, Goodell found “mitigating circumstances” that allowed him to reduce the discipline to one game. As Boomer Esiason said on CBS’s “The NFL Today,” “Who in the NFL decided to take the six-game suspension, part of the policy enacted in 2014, and reduce that six games to one game? What were the supposed mitigating circumstances? I would like to know that answer.”

The answer is that it was done by Goodell, who fought for unlimited disciplinary discretion at the same time he was engaging in a theatrical anti-violence campaign that now looks utterly substantial thanks to him.

“Right now, I am just numb to the incompetence of the NFL,” player-turned-commentator Tedy Bruschi said on ESPN on Sunday. But that’s not the whole truth of the matter. The whole truth is that Goodell is as unprincipled as he is incompetent.

[Tom Brady isn’t about to let the NFL off the hook for its Josh Brown problem]

The league’s investigation amounted to tanking the case, and the facts they did get, they sat on. Meanwhile, Goodell has brought a ferocity to disciplining players on minor issues, from Brady to fining Vernon Davis about $12,000 for a perfectly innocent celebratory display on the field.

Asked to explain this bipolar inconsistency, Goodell replied: “As a professional athlete you’ve got certain standards that you have to meet,” he said. “You have to dress in a certain way, you have to perform in a certain way and within certain rules. And what anyone does on that field reflects on everybody. And off the field. And that’s why we all focus so much on ‘these are the standards we want to meet’ and let’s meet them.”

This is not mere arrogance or superficiality. It’s duplicity. Goodell gets tough with select players on minor issues to mask his weakness on larger ones. He is incapable of real management. He does not know how to arbitrate between owners or balance their interests, or truly adjudicate. He only knows how to suck up to one owner with leniency, while screwing over another in the interest of self-preservation. It’s all an exercise in cover.

Goodell’s clumsy, enabler’s strategy has become obvious — and publicly embarrassing. Indeed, personal conduct “reflects on everybody.” His has tainted the entire NFL as uncaring and hypocritical. Commentators such as Randy Moss reported Sunday that there was significant dissatisfaction with Goodell across the league. “I think the owners are mad,” he said. Goodell’s toadying may gratify individual owners, but it has undermined their collective trust. As well as the public’s.