It is a frivolous question, really, little more than slow-day fodder for New England talk radio.

Is Tom Brady or Bill Belichick more responsible for the New England Patriots’ dynastic success? Like all perfect sports arguments, it’s both pointless and irresistible.

Both the silliness and durability of the debate derive from its unanswerable nature. Brady and Belichick of course share in the Patriots’ reign, and how to divvy up those four Super Bowl titles and six AFC championships is impossible to determine. It sparks instant, endless opinion, enough for a couple guys to argue it over far more than a couple of beers.

If you want to play the “Brady or Belichick?” parlor game, the first two weeks of this season have placed a sizable load on the “Belichick” side of the scale. Without Brady, under the stewardship of Jimmy Garoppolo, the Patriots looked exactly like the Patriots.

They controlled their debut victory in Arizona against the Super Bowl-aspiring Cardinals, and Sunday smoked the Miami Dolphins for three quarters before surviving with a 31-24 victory. The NFL intended to punish the Patriots with its suspension of Brady. After two weeks they are 2-0 and possess full ownership of the AFC East.

After a struggle to beat Miami, which ended only after Ryan Tannehill heaved an interception into the end zone in the dying seconds, it will become much more difficult now.

Belichick and offensive coordinator Josh McDaniels prepared brilliant plans for Garoppolo, a quarterback who designed himself after Brady and never missed a beat. And then in the second quarter Sunday, after Garoppolo had thrown three touchdown passes, linebacker Kiko Alonso sacked Garoppolo and drove his right shoulder into the turf with all of his 239 pounds.

The play explained why the Patriots had to hold on for dear life. Garoppolo stayed down and left for the remainder of the game.

They inserted rookie Jacoby Brissett, a third-rounder out of North Carolina State who, under normal circumstances, would be their third quarterback.

Brissett finished the drive with a field goal, and with a few short passes, long runs after the catch and LeGarrette Blount rushes, led the Patriots to a touchdown on their first drive of the second half. For the rest of the game the Patriots didn’t score. They mostly attempted to run out the clock and leaned on Blount, who rushed for 129 yards.

Brissett attempted only nine passes and completed six for 92 yards.

Belichick may now face one of the most pressing challenges of his New England tenure since the early weeks of the 2001 season, when Brady usurped the quarterback position from the injured Drew Bledsoe and Belichick prevented the locker room from fracturing. That season ended with a stunning Super Bowl title. This one, eventually, will fall back into the hands of Brady.

But this week will provide another chance for Belichick to validate his coaching genius independent of Brady.

The Patriots are home Thursday night against the Houston Texans. Given the apparent likelihood Garoppolo will remain out, Belichick will have three days to prepare a rookie quarterback to face a 2-0 team that has allowed 26 points total. And also fix a defense that allowed 389 yards passing from Tannehill.

It will fall on Belichick, which for the Patriots should be nothing but comforting. Since Brady became the starter, the Patriots have gone 172-51 in games he’s started, a 77.1 winning percentage. In games he’s been injured or suspended, the Patriots have gone 13-5, a 72.2 winning percentage. Belichick managed to squeeze out an 11-5 season with Matt Cassell in 2008 after Brady suffered a season-ending knee injury Week 1.

If Belichick can beat the Texans with Brissett on Thursday, it would not diminish Brady’s career. Belichick and Brady are both on short lists of the best in NFL history to perform their given task. But it would further burnish Belichick’s legend.

The Brady-or-Belichick debate can never be truly settled, but two facts stand out as the Patriots sit at 2-0 and poised to hand the offense to a third-string rookie. We have no way to know what Brady would do without Belichick. We have learned Belichick can win without Brady.