Bill Belichick is arguably the greatest coach in NFL history. But the 73-year-old has a lot of work to do at the college level. 

Belichick made his college coaching debut Monday night as he led the University of North Carolina Tar Heels onto the field for the first time at Kenan Stadium. The building was popping, the hype was off the charts, and Belichick was rocking his usual look with the sleeves trimmed on his UNC football hoodie. 

Celebrities and famous alumni packed the house to watch Belichick's debut against TCU. It started great too, as the Tar Heels ripped off a 83-yard touchdown drive just four minutes into the game to take a 7-0 lead.

Then it all went off the rails for Belichick and his inexperienced squad. With 70 new players on the roster, UNC was demolished by TCU the rest of the way, handing Belichick a 48-14 loss in his collegiate debut.

The 34-point loss is tied for the second-biggest defeat by a Belichick-led team. The 48 points allowed are a new UNC record for most surrendered in a season opener, and is the first time a Belichick-coached team has ever allowed that many points.

The calling cards of Belichick's dominant New England Patriots teams that won six Super Bowl titles were missing Monday night. (It didn't help that the Tar Heels don't have a Tom Brady at quarterback.) UNC made a number of fundamental mistakes and turned the ball over three times to spot TCU 19 points, including a pick-six by quarterback Gio Lopez right after his defense got him the ball with a pick of its own. 

How about the vaunted Belichick-Belichick defense, which is led by Bill's son, Stephen? It couldn't stop anything against TCU, which dominated the line of scrimmage and ran wild for 258 rushing yards, averaging a robust 7.4 yards per carry. Overall, the Horned Frogs racked up 542 yards of total offense.

Fundamentals were lacking too. Late in the first half, Carolina had a bad snap on a gotta-have-it third-and-3 that ended with Lopez heaving a prayer downfield. It fell incomplete and led to a punt, which the Tar Heels also had issues with when punter Tom Maginess completely missed the snap and had to make a miraculous move to get off a 26-yard punt.

TCU added a field goal off that bad special teams play to take a 20-7 lead into the half. It would only get worse from there. The Horned Frogs got a 75-yard touchdown run from Kevorian Barnes on the first snap of the second half. Trent Battle scored on a 28-yard touchdown run on TCU's next possession as the Tar Heels continued to get torched on the ground.

TCU got another defensive touchdown in the third quarter when Lopez was sacked. He fumbled, senior edge rusher Devean Deal then returned it 37 yards to make it a 41-7 game. At that point, the air was completely out of Kenan and the luster of Belichick's debut was gone.

"Obviously, we have a lot of work to do," Belichick said after the loss. "We need to do a better job all the way around - coaching, playing, all three phases of the game." 

It was only one game for Belichick and one against a very talented opponent in TCU. But for the majority of the night, it was crystal clear the Tar Heels roster -- and Belichick as a college coach -- are both very much a work in progress. For all the pomp and circumstance Belichick's debut created, it sure looked a lot like his final seasons in New England, only in much nicer weather.

However, Belichick losing his debut with a new team is nothing new. He also lost his first game as the head coach of the Cleveland Browns and with the Patriots. At least one of those stops worked out pretty well for Belichick.

UNC Alum at Belichick's UNC Debut

Former North Carolina stars came out for Belichick's debut. Another GOAT was in the building in Michael Jordan, who sat with former UNC basketball coach Roy Williams. Former Tar Heels stars Lawrence Taylor (who had Belichick as his defensive coordinator with the New York Giants) and Julius Peppers were also in the building, as was women's soccer superstar Mia Hamm. 

Belichick also had a few former Patriots players in the house in Randy Moss and Tedy Bruschi, who made appearances on ESPN's pregame show. It was on that program that three of the four pundits -- Bruschi, old Belichick pal Nick Saban, and Pat McAfree -- all picked UNC to win because of their close relationship with Belichick.

Moss at least got to celebrate UNC's first touchdown, and did so in a box next to Belichick's girlfriend, Jordon Hudson. It made for an interesting cutaway after the score.

But after that, there wasn't much for UNC fans to celebrate and we were left mostly with Belichick looking like his old self on the sideline - grumpy and angry at the officials. 

Belichick and the Tar Heels are now on to Charlotte, whom they'll visit Saturday night at 7 p.m. The 49ers are coming off a 34-11 loss to Appalachian State.