CHAPEL HILL – Perhaps lost amidst all the wrangling over North Carolina’s losses at Virginia and Florida State is a part of most every game that can sometimes define the line between winning and losing, though it’s rarely discussed.

It’s called “sudden change defense,” and it basically means that moment when a defense is summoned to the field unexpectedly because of a turnover or special teams snafu. In some cases, like early in the loss at FSU a few weeks ago, the defense is preparing to go onto the field, but instead of defending well into the opponent’s territory, it starts in the shadow of its own end zone.

Instant stress. And on four occasions this season, it’s meant nearly and instant touchdown for UNC’s opponents.

Sudden change defense is a problem, and the coaching staff knows it.

“Honestly, I think that’s been one of our biggest issues,” UNC defensive coordinator Jay Bateman said during Monday’s weekly press conference. “I don’t think we’ve done a great job… When you get put in that situation you have to go out and rely on your training and your fundamentals and do it right. And I think we’ve pressed too much.”

In the second quarter of UNC’s win at Boston College, a botched kickoff return forced the Tar Heels to begin that possession at their own 5-yard-line. On second down, Sam Howell’s tipped pass was intercepted, and three plays later BC scored a touchdown. So, the Eagles scored 10 points in 63 seconds turning a 14-3 UNC lead into a 14-13 game. UNC won, 26-22, but had BC scored on a two-point conversion late, that touchdown would have obviously loomed awfully large.

Florida State blocked a Carolina punt on the first possession of the game a few weeks ago in Tallahassee, and on the very next play – FSU’s first snap of the night – the Seminoles scored on a 23-yard run and later defeated the Tar Heels 31-28.

It happened twice this past weekend in Charlottesville.

Toe Groves fumbled a punt late in the first half giving Virginia the ball at UNC’s 20. Three plays later, the Wahoos scored a touchdown. Then, in the third quarter, UVA recovered a Howell fumble at Carolina’s 30-yard-line and scored a touchdown five snaps later for a 41-20 lead with 5:34 left in the period. The Hoos won the contest, 44-41.

Considering the Heels lost two of those games by a mere field goal, it’s rather clear Carolina could have won had the defense forced field goals instead of allowing touchdowns in those sidden change situations.

Bateman doubled down on one of his theories while offering a deeper explanation of why this is an issue for the Heels.

“After the dropped punt on Saturday, we had a play that I would have bet $100 that we were going to defend perfect, (but) we were too aggressive on the routes,” he said. “We’ve got to just go do our job and rely on fundamentals and do our one-elevens, and I think we’re pressing.”

UNC Coach Mack Brown says older, more veteran defenses tend to handle the stress of sudden change situations better because they know the ropes.

“They handle tackling better, they handle sudden change better, they handle critical plays better, they don’t have as many penalties,” he said. “They’ve played a lot of ball.”

Carolina currently fields a bit of a younger group on defense, especially in the secondary. Brown said the room was the deepest he's been around when fall camp started in August, but now players with just handfuls of games under their belts are being asked to play major roles.

"You’re down seven guys and that’s a lot of your run fits," Brown said. "You’ve got guys who haven’t been out there very much trying to cover people and play action and it’s a difficult thing."

Practice allows for only so much simulation, but these scenarios are certainly regularly addressed.

“It is a mindset,” Brown said. “And that mindset, sometimes we even stage it in practice: ‘Sudden Change, Sudden Change, put the fire out.’”

One of the other problems, Bateman said, is the players are trying to put out fires that are outside of their responsibility zones. It’s not hero ball, as some call it, it’s more a deep desire to simply make plays.

But branching beyond one’s assignment can be costly.

“I think it’s more, ‘Okay, I’ve got to go make a play, I’m gonna go out here and I’m gonna get a stop, I’m gonna go get a TFL,’” he explained. “And all of a sudden your eyes are not in the right spot or you’re not defending your gap, you’re not on the right man and then breakdowns happen. And I think that’s what’s happening.”

It’s happened too often and has been too damaging to the Tar Heels. Among the things that need mending, this is near the top of the list.