PITTSBURGH (AP) — Darrin Hall broke through the line of scrimmage and saw nothing but green grass in front of him. Finally.

About 10 seconds and 92 yards later, the Pittsburgh junior running back reached the end zone to finish off the longest touchdown run in the history of a program that dates back 127 years.

It was part of a rare breakout game by a back in the Atlantic Coast Conference this season.

"It's frustrating when we're out there, we get our shot and we don't make plays," said Hall, who finished with a career-high 254 yards rushing and three scores in a victory over Duke last Saturday.

Hey, it's the same frustration being felt around in the ACC, where defenses, depth concerns and the departure of NFL-ready talent have left a bit of a vacuum at running back.

As Halloween nears, two of the top three rushers in the league are quarterbacks. Taquon Marshall is averaging 117 yards a game while piloting Georgia Tech's run-heavy triple option, a bit ahead of teammate KirVonte Benson. Reigning Heisman Trophy winner Lamar Jackson is third at 108.5 yards a contest.

If Marshall or Jackson end up leading the league by season's end, it'll mark the first time in ACC history a non-running back has led the conference in yards on the ground. No other Power Five conference has two quarterbacks in the top three in rushing, though Pitt coach Pat Narduzzi believes trying to classify Jackson as anything other than a football player is a semantic argument at best.

"Lamar's a running back," Narduzzi said. "He's a back. That guy can run."

Jackson isn't the only one. Marshall is averaging a healthy 4.9 yards per carry. At Syracuse, high-flying Eric Dungey — who's made a habit of playing leapfrog when he escapes the pocket — leads the surprising Orange in rushing and has already tied the school record for career rushing touchdowns by a quarterback.

Of course, Jackson, Dungey and Marshall have one decided advantage over every other player on the offense: they get to touch the ball every play. Combine that with their athleticism and well, why not let them just run loose. Four Power Five conference quarterbacks have at least 100 carries this season. All four of them play in the ACC.

"Like I say, (Jackson is) deer-like, you know what I mean?" said Florida State coach Jimbo Fisher, who got an up close look as Jackson ran for 178 yards in a win over the Seminoles last weekend. "That fast twitch that can just jump sideways. Like I tell him, I ain't never seen a deer be slow, ain't never seen a deer need to stretch."

Besides, Jackson, Dungey and Marshall never leave the field. That's not the case for running backs who are at the mercy of everything from game situation to the mood of their coaches on a given day.

"I love to keep the guys fresh and the thing that's good for me is that all those guys can go in and function at a high level," Clemson co-offensive coordinator Tony Elliott said. "Whereas in the past you might have had one guy you knew you could trust in all situations and then you had situational guys."

Not so much anymore. Considering the pace most teams try to play at, the idea of giving the ball to one guy 30+plus times can be tough if you're snapping it every 10-15 seconds. The Tigers have five players with at least 28 carries this season. Wake Forest has five with at least 37. Pitt has eight with 15 or more.

"I think each team, each situation is going to be different depending on the player, depending on the health, depending on the system," Elliott said. "There's a lot of factors involved. I've always said I want to have at least three guys that can go and it's a luxury to have four."

Only Boston College's A.J. Dillon (152 carries) and Virginia's Jordan Ellis (142) qualify as guys carrying the load.

If Narduzzi had his preference, one of the four backs he's tried to feature this season would be on the list. Yet Hall, Qadree Ollison, Chawntez Moss and A.J. Davis have found success only in small pockets.

Ollison was the ACC offensive Rookie of the Year in 2015 when he ran for over 1,100 yards after Conner went down with a knee injury and appeared to be Conner's heir apparent this summer after Conner left for the Pittsburgh Steelers. Instead, Ollison struggled to find any sort of consistency and spent last weekend serving as a lead blocker for Hall.

The Panthers were 21st in the country in rushing in 2016. They find themselves 88th this season. Then again, the sledding is tougher all over. Four ACC schools averaged more than 35 points a game in 2016. No team is averaging more than N.C. State's 33.5 this season.

Pitt set a school record by averaging 40.9 points in 2016. The Panthers are averaging barely half that (20.5) now. Blame it on the departure of Conner and quarterback Nate Peterman to the NFL and a shift to new offensive coordinator Shawn Watson.

Narduzzi is open to pretty much anything to get Pitt going. Just don't expect Hall to find himself lined up at quarterback. First, he said, "I'm a lefty and I can't throw." Second, he believes running backs will be back in vogue soon enough.

"The read-option, the triple option, it's big in the ACC and we run a little bit ourselves," Hall said. "I feel like it's just being able to execute. You execute what you're good at. We stick with it, we'll be fine."

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AP Sports Writers Joe Reedy in Tallahassee, Florida, Pete Iacobelli in Columbia, South Carolina and John Kekis in Syracuse, New York contributed to this report.

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