Pass rush has become the key requirement for defenses in the modern-day, pass-happy NFL.
Although elite pass-rushers rely on speed, agility and strength, it is not strictly a young man's game. There are a clutch of veterans over the age 0f 30 who consistently prove that even greybeards can still bring the pressure play after play.
Among the very best of this evergreen collection is a talented Indianapolis Colts double act and a Pittsburgh Steelers ace who began life as a training camp casualty of the Baltimore Ravens.
Here are the top five pass-rushers over the age of 30 who are still terrorising NFL quarterbacks.
Jason Babin simply gets better with age. The 32-year-old has posted 30.5 sacks in the last two seasons since joining forces with line guru Washburn.
Babin has perfected the wide-9 alignment and four-point stance. The speed of his takeoff often takes the 6'3", 267-pounder beyond an offensive tackle before the tackle is even out of his stance.
Babin was lethal in his first year in Philadelphia, recording 18 sacks and forcing three fumbles. In unison with Jenkins and Trent Cole, Babin should be just as good this season.
31-year-old Robert Mathis remains as cat-quick and technically refined as ever. The 10-year pro is still one of the more prolific pass-rushers in the NFL.
Mathis relies on explosive takeoff quickness to beat blockers to the edge and exceptional closing speed to chase down quarterbacks. A master of the strip sack, Mathis has forced 39 career fumbles and is a big-play specialist.
He has spent much of his career living in the shadow of partner in crime Dwight Freeney, but Mathis has started to come into his own as he has gotten older. He was the lone bright spark on an abysmal Colts defense in 2011.
A switch to a hybrid 3-4 role should still yield positive results for Mathis. The 6'2", 245-pounder has the ideal frame and range of movement to excel in the Colts' new schemes and may finally outshine Freeney.
4-3 veteran Dwight Freeney faces a tough transition to the Indianapolis Colts' new hybrid 3-4 schemes. Freeney has more of a squat build than Robert Mathis and looks more like a traditional defensive end.
The 32-year-old has been one of the most dangerous pure pass-rushers in the NFL since entering the league in 2002. Freeney has notched 102.5 career sacks and forced 43 fumbles.
His blend of first-step quickness, closing speed, raw power and leverage makes Freeney still as dangerous as ever as he enter his 11th season.
Noted for his famous spin move, Freeney is also adept on the bull rush and is an expert at fooling blockers with his hands.
If Freeney can adapt to his new role, he should return to his very best during a contract year. Considering Freeney and Mathis have rarely, if ever, benefited from the presence of elite defensive tackles, their consistent sack totals are all the more impressive.
Despite beginning life in the pros as a rookie free agent, James Harrison continues to be one of the most feared 3-4 pass-rushers in the league. Since the Steelers' Super Bowl triumph in 2008, teams have begun to pay special attention to the nine-year-veteran.
Yet, despite facing regular double teams, the 6'0", 242-pounder still manages to be a consistent threat to opposing quarterbacks. Harrison relies on superb natural leverage and deceptive upper body strength.
Working for the great Dick LeBeau has helped Harrison channel his considerable aggression and refine the overall technique of his game. That's led to 54 sacks since 2007.
Although Harrison dropped just below the 10-sack mark in 2011, don't be surprised to see the 34-year-old post a double-digit tally this season.
13-year pro John Abraham is the best veteran pass-rusher in the NFL. The 34-year-old continues to be the most feared member of the Atlanta Falcons defense.
Since joining the Falcons in 2006, Abraham has collected 58.5 sacks. His form coincided with revival the NFC South team has experienced under head coach Mike Smith.
When Smith joined the team in 2008, Abraham became the biggest playmaker on the defense. His 16.5 sacks that season played a significant role in getting the Falcons into the playoffs.
What separates Abraham is his intelligent technique. He is one of the more skilled and versatile pass-rushers in the league and ahas a wide variety of moves.
The Falcons have been smart with Abraham and have used the 34-year-old in a situational role to keep him fresh. He was superb in 2011, recording 9.5 sacks, deflecting two passes and forcing four fumbles.
Abraham doesn't have the advantage of a strong supporting cast up front and relies on smarts and technique to still pose a threat to any quarterback.
The likes of Jason Pierre-Paul and Aldon Smith may hog the headlines as young playmakers, but these veterans still have plenty of life left as pass-rush specialists.