CHAPEL HILL — ACC football players and coaches often speak in ominous tones about the specter of facing Georgia Tech’s triple-option offense, but a commonly-held belief is that an extra week to prepare for it can be the difference between effectively defending it and appearing lost.

North Carolina, which didn’t play a game last weekend, had that extra week to prepare for the Yellow Jackets. Yet that hardly seemed to matter on Saturday, when UNC suffered a 68-50 defeat against Georgia Tech that left Larry Fedora, the Tar Heels’ first-year coach, without an explanation or answers.

“I don’t have any answer for you right now,” Fedora said when asked to explain how his defense allowed 588 yards of offense – 380 of them on the ground.

Though Fedora wasn’t prepared to detail the technicalities of what went wrong, the Tar Heels’ problems, in a general sense, were likely obvious to even the most casual of observers at Kenan Stadium. Defensively, UNC (6-4, 3-3) forced just one punt before the fourth quarter, and allowed touchdowns on eight of the Yellow Jackets’ first 10 drives.

Offensively, the Tar Heels had two turnovers that directly led to 10 points. And on special teams, UNC allowed a 100-yard kickoff return for a touchdown. That play, the first of the second half, gave the Yellow Jackets (5-5, 4-3) momentum they never seemed to relinquish, even after UNC briefly reclaimed the lead on its next offensive play on Giovani Bernard’s 78-yard catch and run for a touchdown.

“We played poorly in all three phases of the game,” Fedora said. “Offense, defense and special teams.”

But especially on defense. The defensive futility of both teams allowed Georgia Tech and North Carolina to set records. They combined for 118 points, the most ever in an ACC game between league teams, and the most ever in any game involving an ACC team.

But while Georgia Tech’s defense was bad – it allowed the Tar Heels 497 yards of offense – UNC’s was worse. Never before in the 59-year history of the ACC had a team scored more points than the Tar Heels’ 50 and lost.

“I feel bad,” Sylvester Williams, the UNC senior defensive tackle, said. “And I’m sorry. I want to apologize to my coaches.”

Try as Williams might to accept blame, there was plenty to go around. Williams and his teammates on the defensive line routinely allowed Georgia Tech ball carriers to break into the defensive backfield. The Tar Heels’ linebackers and defensive backs, meanwhile, failed to shed blocks or to prevent long plays.

UNC rotated between a three-man defensive front and a four-man defensive front. Neither worked.

Perhaps worst of all, the Tar Heels allowed 208 yards passing. The run-first Yellow Jackets hadn’t thrown for that many yards against any ACC team this season, and the 208 passing yards represented Georgia Tech’s third-best passing output against an ACC team since coach Paul Johnson brought his triple-option to Georgia Tech in 2008.

“Yeah, they’re known as a running team,” Tim Scott, a sophomore UNC cornerback, said. “But when they’re running, running, running, they’re going to give you a couple of play-action passes.

“So when they did do so, we weren’t prepared for it.”

Scott made his team’s best defensive play of the game when he intercepted a pass and returned it 34 yards for a touchdown on the first play of the fourth quarter. After UNC had allowed 30 third-quarter points – seven more than the Tar Heels had allowed in the third quarter all season, entering Saturday – Scott’s return cut Georgia Tech’s lead to 58-50.

But the Yellow Jackets responded with a 7-play, 81-yard touchdown drive that was as methodical as it was typical of the events on Saturday. Orwin Smith, Georgia Tech’s senior running back, ended that drive with a 22-yard touchdown run that gave the Jackets a 65-50 lead. UNC never again threatened to score.

Vad Lee, a former standout at Hillside High in Durham, led the Yellow Jackets with 169 yards passing and 112 yards rushing. He ran for two touchdowns in the first half and passed for a touchdown late in the third quarter that gave Georgia Tech a 58-36 lead.

Afterward the Tar Heels, who led 29-28 at halftime, had difficulty explaining their breakdowns. Had an off week made them rusty? Had they found it difficult to become motivated after a dramatic 43-35 victory against N.C. State in their most recent game before Saturday?

Kevin Reddick, the senior linebacker, explained what went wrong like this: “Discipline, man. That’s all it was. Like I told the guys, this game was going to tell how disciplined we were.”

More than most offenses, Georgia Tech’s triple option requires defensive players to remain disciplined, and focused on specific assignments. The Tar Heels, though, routinely failed to keep their assignments on Saturday.

That came as a surprise to Fedora, who said the Tar Heels had practiced well in the days leading into Saturday. His players said afterward that they didn’t see this kind of performance coming, and it blinded Fedora, too.

“If I would have saw that coming,” he said, “I probably wouldn’t have shown up today.”

Carter: 919-829-8944