No man is an island, but when you're Julius Peppers, a defensive end with the athleticism to suck up tailbacks from 70 yards away and to line up at receiver in the red zone, you want to be on one as often as possible, pursuing the quarterback from the most advantageous position.
Peppers is at his best when he's rushing from the edge, wide of the tackle or over a tight end, in what's known as the "7" technique. Peppers (6 feet, 6 inches and 290 pounds) has ideal size to play on the interior, and for a brief period during the first month of the season, Carolina, looking to take advantage of their linebacker depth, experimented with using Peppers inside, over the tackle in the "5" technique, at end in their 3-4 package. Make that misusing him.
A former "4" (power forward) for The University of North Carolina hoops team, Peppers learned that battling inside on the gridiron is a whole different ballgame. His production slipped in those and he looked, according to one pro scout, hesitant.
"I really don't like being down inside," said Peppers, who, at home on the edge, has posted eight of his 10 sacks this season in the past six games. "I feel like when I'm down in that area like a tackle, I don't feel like I'm being used properly. It's hard, because you have to be a lot more run conscious and a lot more physical, which, being physical, that's no problem for me. But I'd rather get on the edge and rush the passer."
Wouldn't they all. Look at it this way, Julius: At least your 3-4 days are over. There are linemen in Baltimore, Houston, New England, Oakland, Pittsburgh, San Diego stuck doing the defense's dirtiest jobs week in and week out.
The primary defensive front for the aforementioned six franchises is the 3-4, which includes three defensive linemen -- a nose tackle lined up over center flanked by ends over each tackle -- and four linebackers, two inside and two outside. Majority rules in this scheme, which several other teams also have in their personnel package. It's designed to feature the 'backers. They're the stars, while the linemen's primary responsibility is to help the 'backers look their best by keeping offensive linemen occupied. Their contributions can't necessarily be measured by individual statistics. At least, not their individual statistics.
Think of the big boys up front as production assistants. They get about the same amount of recognition, too. Very little.
"It's not that hard," said Patriots nose tackle Keith Traylor, who had limited experience in the 3-4 before this season, "it's just boring. It's not a lot of fun."
Indeed, for 3-4 linemen, the action in the playmaking department rarely is fast and furious. All 3-4 teams use some style of the "two-gap" technique, which calls for the nose tackle to fill the "A" gaps on either side of the center and for the ends to take care of the "B" and "C" gaps between the guards and tackles and outside the tackle, respectively. The idea is to fill both gaps and delay, if not prevent, blockers from reaching the second level, thereby creating open lanes to the football for the inside linebackers.
Pittsburgh's linemen do lots of stunting (looping) and penetrating, forcing the ballcarrier to commit to a hole. The Patriots linemen, on the other hand, are asked to simply hold their positions and tie up blockers. In general, linemen in the 3-4 often aren't in the best position to make tackles, hence their typically low totals. And since they aren't shooting through gaps like 4-3 linemen, they don't make very many stops behind the line of scrimmage, either. That's particularly true for the nose tackles, who deal with more of a variety of double teams than their 4-3 counterparts, who are already aligned in gaps.
Sacks are a bonus for pocket-pushing nose tackles, like an onion ring in your French fries; Baltimore's Kelly Gregg, maybe the best nose in the game along with Pittsburgh's Casey Hampton, has 1½. Ends in the 3-4 tend to collect a few more, but they are inhibited by their responsibilities versus the run and don't put up the same kind of numbers as 4-3 ends.
Before an end can get after the quarterback, he has to first make certain a draw isn't coming through the "B" gap (between the guard and tackle). The end also has bootleg duty. If there's run action inside, the ends first reaction should be to hit the "B" gap, and if nothing's coming, hustle back outside to contain the quarterback.
"The responsibility of a 3-4 end is 10 times harder than the responsibility of a 4-3 end," said Pittsburgh end Kimo von Oelhoffen. "You're on the edge (in the 4-3). You've got great angles for stopping the run, and great angles for rushing the quarterback. That's why those guys get sacks."
All of which makes Steeler Aaron Smith's eight sacks all the more impressive (Patriots DE Richard Seymour had eight last season). Smith's eight sacks tie him for 15th in the league. Next among 3-4 defensive linemen is Baltimore's Marques Douglas, who has 5½, tied for 38th in the league.
Smith and Seymour are considered the league's top 3-4 ends because they're strong against the run and the pass. Seymour has made the last two Pro Bowls. Long (6-6, 310) and athletic, he's considered the prototype for the position the way 365-pound Ted Washington was for the nose. People in Pittsburgh are lobbying for Smith to be the team's first Pro Bowl end since L.C. Greenwood after the '79 season.
One number says it all about the difference between playing defensive tackle in a 4-3 and end in a 3-4, similar positions in terms of physical stature. The number is one. That's Warren Sapp's sack total this season.
"It takes a special cat to really play within the structure of the defense and be unselfish and all the things that come with it," said Ravens defensive line coach Rex Ryan, who's brother, Rob, coordinates Oakland's defense. "Warren Sapp's one of the best 4-3 tackles of all time. You'd think he'd be able to do it (convert to end), but, and I don't get to see their games, but something's not happening over there."
"It's not designed for you to make the plays," said Seymour, who has four sacks this year. "It's designed for the linebackers. That's why it's a 3-4. You've really got to do a good job to get yourself into it, but you're creating for other people."
If stats are your thing, and you're looking to others to define your value to your defense, then the 3-4 isn't for you.
"You have to be an unselfish player," Ryan said. "If you're playing like you're in an Indianapolis scheme and getting up the field and all that, you would not be able to stop a run to save anything. Those (3-4) guys have gotta two gap. They've got to do all the dirty work."
Michael Smith is a senior writer for ESPN.com.