Post NFL editor Keith McMillan recruits a few coworkers to see if they can tell which football has been under-inflated by 2 PSI, the amount the NFL claims the New England Patriots’ game balls were deflated. (Davin Coburn and Jason Aldag/The Washington Post)

In 10 days, the New England Patriots will attempt to extend their dynastic run atop the National Football League. The Patriots’ offense, led by the grace of quarterback Tom Brady and the grim formulation of Coach Bill Belichick, will attempt to unseat the reigning Super Bowl champion Seattle Seahawks, their defense spearheaded by Richard Sherman.

Yet the nation’s most heated sporting debate revolves around the proper amount of air inside a football.

An alluring Super Bowl matchup has given way to an even more captivating subplot this week. The NFL’s investigation into whether the Patriots improperly deflated footballs in the AFC championship game against the Indianapolis Colts — thereby giving Brady and his receivers a better grip on the ball in rainy weather — has raised more intrigue than even the game itself. Entering their sixth Super Bowl in 14 years, the Patriots again find themselves swathed in a controversy that calls into question the ethics of their two most famous faces: Brady, the golden boy quarterback, and Belichick, the wicked genius coach.

Apart from the arcane specifics of the incident — allegations league officials regard as “very serious,” a person familiar with the league’s deliberations said Wednesday — the episode has spurred larger questions. What is the line between gamesmanship and fraud? Could their potential punishment affect the Super Bowl? Can the Patriots’ dominance over more than a decade be separated from their alleged — and, in some cases, proven — underhandedness? And since when could the pounds per square inch of air pressure of a pigskin cause so much fuss?

“Listen, if they did it, then it’s cheating,” former Jacksonville Jaguars offensive tackle and likely Hall of Famer Tony Boselli said. “If you did it, if you cheated, there needs to be consequences. It depends if they all knew or if there was a mistake or it was oversight. A lot could go into it.”

The Post Sports Live panel weighs in on how the NFL's investigation into whether the Patriots deflated footballs before their AFC championship game against the Colts affects the team's legacy. (Post Sports Live/The Washington Post)

Most of those details involve specifics almost no one cared about last week. According to an ESPN report, the footballs were under-inflated by two pounds per square inch of air pressure. NFL rules require the footballs to be inflated to between 12.5 and 13.5 pounds per square inch and to weigh from 14 to 15 ounces.

On Wednesday, Boston radio station WEEI reported the under-inflated balls were taken out of play after the first half and backup balls, all properly inflated, were used in the second half.

Under NFL rules, each team provides footballs for use while it is on offense. The game officials inspect the footballs prior to kickoff, and the balls then are given to attendants who are provided by the home team — not by the league.

Manipulating footballs, several NFL officials said, surely happens all across the league, and quarterbacks have particular preferences. One NFL assistant coach said he had heard of — but never seen first-hand — quarterbacks slipping an inflation needle into their socks in order to adjust footballs on the sideline. Former NFL quarterback and Heisman Trophy winner Matt Leinart wrote on Twitter: “Every team tampers with the footballs. Ask any Qb In the league, this is ridiculous!!”

Boselli, now a Jaguars assistant coach, spoke on the field at Ladd-Pebbles Stadium in Mobile, Ala., where hundreds of NFL team officials have descended for the Senior Bowl, an annual showcase for draft prospects and something of a spring break for scouts and coaches. Late at night, with the aid of adult beverages, the Patriots’ latest alleged malfeasance has dominated conversation — a mix of simmering resentment and grudging respect: That Belichick will do anything to win. But, man, he sure does win a lot.

As the Patriots have won three Super Bowls and lost two others in recent years by slim margins, they also faced one of the NFL’s largest scandals and whispers of further underhanded tactics.

In September 2007, NFL Commissioner Roger Goodell fined Belichick $500,000 and the team $250,000 after the league determined the Patriots had illegally videotaped opposing coaches’ signals — the scandal that earned the moniker “SpyGate.” Goodell also stripped the Patriots of a first-round draft selection.

That case led to a trickle of other allegations of Patriots envelope pushing. In a 2005 playoff game at New England’s Gillette Stadium, the Jaguars lost their coach-to-quarterback communication for the entire first half. Coach Jack Del Rio said later his team’s headsets “mysteriously malfunctioned.”

Some in the NFL believe the Patriots over the years have committed deep violations against competitive fairness. Others think everyone seeks out any advantage they can find and that Belichick just finds more, better ways to do it.

No one believes the Patriots beat the Colts because of their footballs. On the other hand, no one wants to let them off the hook if they bent a rule.

“Whether they had over-inflated, under-inflated or properly inflated footballs, I think they’d be okay with Tom Brady,” Boselli said. “I think it’s a big deal because out of the spirit of the game and following the spirit of the rules, I think it’s important. But I think they’re winning that football game either way. But it’s important people follow the rules.”

The subject has also dominated life inside the NFL offices in New York. ESPN reported late Tuesday night that the NFL has determined 11 of the 12 footballs the Patriots used in their 45-7 trouncing of Indianapolis had been deflated. The league has yet to determine how that happened after referees performed a standard pregame check without incident.

Some have called for the suspension of Belichick or Brady from the Super Bowl. The person with knowledge of the NFL’s deliberations said it is “too early” to determine potential penalties if the investigation shows the Patriots improperly deflated footballs.

“A deflated football is an advantage for a quarterback to throw and a receiver to catch in the conditions they played in Sunday,” said former Washington Redskins general manager Charley Casserly, who once sat on the NFL’s rule-making competition committee. “Regardless of that, if the ball is deflated below what it’s supposed to be, that’s a huge issue. If one team has deflated balls playing at any point, especially in bad weather, that’s a huge advantage. And the Patriots should be punished.”