North Carolina will get a unique test this weekend from Virginia's 3-4 defensive approach, which Cavaliers head coach Al Groh learned during his time as an assistant to Bill Parcells in the National Football League. The Cavaliers employ two defensive ends, one down tackle, which can also be called a "nose tackle," two middle linebackers and two outside linebackers.

"They (Virginia) are a totally different defense than the previous two teams (we've played)," said UNC head coach Butch Davis. "Predominantly, they were 4-3 concept teams. This is a 3-4 concept team. You can see Virginia's background from the NFL. Coach (Al) Groh, having coached with Bill Parcells many years, there's tremendous elements of the 3-4 defense that they ran with the New York Giants."

The Cavaliers come to Chapel Hill with a 1-1 record, having lost 23-3 on the road at Wyoming, and struggling for much of their contest with Duke at home before pulling out a 24-13 victory. The UVa defense is currently seventh overall in the ACC with an average of 340.5 yards allowed per contest. The Cavaliers ranked just ahead of UNC's defense, which is eighth overall.

One area in which the two teams are a little more separated is in the run defense category.

While the Tar Heels have been improved against the run thus far this season, allowing an average of 107 yards, the Cavaliers have allowed 141.5 average rushing yards against their two opponents. Johnny White and the other UNC tailbacks look to exploit this vulnerability in Virginia's defense on Saturday.

For White, adjusting to Virginia's 3-4 scheme involves knowing where his blockers are going to be, as the Tar Heels will use different techniques against this particular defensive approach than they did in their first two outings.

"We have different blocking schemes that you use, but other than that, you run the same plays," said White.

Despite their struggles against the run, Virginia has successfully been able to put pressure on opposing quarterbacks thus far this season, as the defense currently ranks second in the ACC with nine sacks.

"One of the things that you don't generally associate sometimes with a 3-4 team is the number of sacks. In two ball games, they've already gotten nine sacks," said Davis. "They really put pressure on the quarterback, and I'm sure that's going to be a major challenge for our offense this week, is making sure that we are good in our protections."

The biggest contributor in the sacks department has been senior Chris Long, who leads the ACC with four sacks and a loss of 32 yards. Long, whose father Howie is an NFL Hall of Famer, received high praise from Davis for his talents.

"Chris Long, I had the misfortunate at times of coaching against his father, Howie, when he was with the Oakland Raiders, and you want to talk about a 'chip off the old block,' said Davis. "I mean, this is a young man that plays absolutely lights-out football. He is flying to the football. He is big. He is strong. He anchors."

While Long most often lines up against the opposing team's left tackle, he has also been used on the inside in certain formations, lined up over guards. Based on the varying blitz packages the Cavaliers employ, they can line up Long in several different gaps.

"They move him (Long) around a lot; they really do," said Davis. "Predominantly in basic run down situations, he's their right defensive end, but you can see in these two (previous) ball games, he's been everyplace from over at the left guard, the right guard, the left end, the right end. They're moving him around in different situations and different blitzes. They've got all the 3-4 "Zone Dog" schemes that just about every 3-4 team has, and they make great utilization of him. He is a very talented football player."

One of the biggest keys to effectively utilizing the 3-4 defense is having big, fast linebackers than can cover ground and make plays all over the field.

Three of Virginia's four starting linebackers are at least 240 pounds, and two of them (juniors Clint Sintim and Antonio Appleby), are at least 6-3 in height, which will present its own set of challenges to the Tar Heels on Saturday.

"Their linebackers are 6-2, 6-3, 6-4, 240-pound guys. They look like the prototype of the 3-4 scheme," said Davis. "They are very fundamentally sound. They're big. They're physical."

Virginia has had a great deal of defensive success in recent outings against North Carolina, shutting out the Tar Heels, 23-0, last fall in Charlottesville, and holding UNC to one touchdown in a 7-5 loss in Chapel Hill back in 2005.

With a new coaching staff prowling the North Carolina sidelines this time around, however, the Tar Heels are hopeful to overcome their recent woes moving the ball against the Cavaliers and find a way to get a crucial victory in the ACC Coastal Division.

For Davis, Saturday's contest will be just another opportunity for him to learn about his new team.

"I've got to be honest. This whole football team is kind of a revelation to me. It really is," Davis said. "I mean, you watch them in practice and go through spring. That sometimes doesn't tell you everything. You don't really know about your football team until you go through the trials and tribulations, until you go through challenges, good times and bad times, until they get into the game and play with game speed."