Amateurism is the core of the NCAA business model.

This oxymoronic idea faced its latest legal challenge in a courtroom in Lower Manhattan over the past three weeks. The trial ended Wednesday, when a federal jury ruled that a “street agent” (my quotes) and two men who work for Adidas were guilty of wire fraud and conspiracy to commit wire fraud.

The defendants were caught, by the FBI, making payments to recruits to steer the players to Adidas-outfitted universities. In this case, the schools were the University of Louisville, the University of Kansas and North Carolina State University.

Really, it could have been anybody with three stripes on their shoes. Nike got lucky. So did Under Armour. The FBI strung up a big fish — in this case, Rick Pitino at Louisville — and then packed up its college-basketball operation and handed its work over to government lawyers.

The jury bought the argument that paying and steering the players rendered them ineligible and exposed the universities to NCAA violations. The jury was actually swayed to believe that the universities were naive victims in all of this.

The government has some fine lawyers.

The defendants argued that by delivering talented basketball players they were helping and not hurting the universities. The defendants were altruists and not capitalists. Bless their hearts.

Conversely, the defendants also argued that they were merely random globules of fat, so to speak, amid the fetid underbelly of the sport. They described how a shadow economy — teeming with unregulated AAU coaches, unregulated summer camps, unregulated savvy street agents, desperate college assistants and willfully blind head coaches — has exploited middle- and high-school kids for decades.

Which is true — but the jury didn’t buy it.

The government has some fine lawyers.

The NCAA will say that this is a victory for amateurism in college sports. OK. We’ll see what happens next year, when two more federal trials – involving assistant coaches, sports agents, “advisers,” Adidas guys and bribery — get underway.

It will be another challenge to a business model that has amateurism at its core. Don’t think about the concept. Just enjoy.

Basketball remains the NCAA’s biggest money-maker: March Madness revenues have passed $1 billion, which accounts for about 90 percent of the NCAA’s budget.

Indentured labor makes it possible. The players know this, which is why many of them take money from street agents, shoe companies and assistant coaches. That is the market for their services. In the grand scheme of things, it’s pennies on the dollar.

The truly big money is big-time college football. Since 1984, when the NCAA lost an antitrust case to the University of Oklahoma and the University of Georgia, individual schools have had the right to negotiate their own television contracts. Football is king.

According to the latest Forbes estimates, Ohio State has the fifth-richest football program in the country with $120 million in revenues and $69 million in profits. Texas, the perennial champion, slipped to No. 2 behind Texas A&M — which has $148 million in revenue and $107 million in profits. Higher education!

To Nick Bosa and others like him, I say: Viva yo, get healed up and ready for the draft, it’s time to get paid.

Part of the historical arc of all of this is the subjugation of high-school coaches. Most of them used to be teachers, who, generally speaking, had the best interest of their students at heart. Over time, an increasing number of out-of-building specialists have taken coaching jobs and assumed influence. This, as the stakes have skyrocketed.

The shadow market was always there — but now it’s a well-developed machine. This is especially true in the big-time basketball racket, notably during the one-and-done era. With the more recent development of 7-on-7 summer football, it will become increasingly true in the big-money sport. Bank on it.

If the folks at the NCAA don’t like it, they should change their business model or budget for more lawyers.