Linebackers are often regarded as the quarterbacks of the defense. They roam the field, and are involved on almost every tackle of every play they see. They deliver the monster hits we see on television each week, and having a dynamic middle linebacker is the key focus of almost every team.
So who is the best middle linebacker in the National Football League right now?
This slideshow features 10 of the premier players at the position, along with highlights of their bone-crushing hits!
Paul Posluszny hasn't been exactly what most would call a household name, after being sent to the Siberia of the NFL, the Buffalo Bills.
"Poz" was selected 34th overall in the 2007 NFL Draft, out of Penn State, and was the recipient of the 2005 Dick Butkus Award.
Posluszny has been plagued by injuries for most of his professional career, but still manages to put up Pro Bowl-caliber numbers.
Last season in just 11 games, Posluszny managed to make 110 tackles, one sack, three interceptions, three forced fumbles, and deflected four passes. His six turnovers were tied for most in the NFL by a middle linebacker.
Signed as an undrafted free agent out of Kent State in 2002, Harrison has made his presence known as a member of the Pittsburgh Steelers. Since making the team, he has been named to three Pro Bowls, and was a winner in two Super Bowls.
Harrison is always making plays and imposing fear in offensive players.
Last season, he made 79 tackles, 10 sacks, and forced five fumbles.
Ryans was destined for greatness by the time he stepped onto the field for the Alabama Crimson Tide. He was named the SEC's Defensive Player of the Year in 2005, and was selected with the first pick in the second round of the 2006 NFL Draft by the Houston Texans.
Ryans had an astounding rookie season, recording over 150 tackles, was named the Defensive Rookie of the Year, and made the Pro Bowl.
Last season, Ryans made 123 tackles, and had a sack. At just 26 years old, it is scary to think that he still has room for improvement.
Vilma was selected with the No. 12 overall pick in the 2004 NFL Draft by the New York Jets, out of the University of Miami. As a Hurricane, Vilma was a semifinalist for the Dick Butkus Award, and finished his collegiate career with over 350 tackles.
Vilma's success continued into the National Football League, where he was named Defensive Rookie of the Year, after recording 107 tackles, two sacks, and three interceptions.
In 2008, Vilma was traded to the New Orleans Saints for third and fourth-round draft picks.
Last season, he made 110 tackles, two sacks, three interceptions, and defensed eight passes en route to a Super Bowl victory over the Indianapolis Colts.
Dansby, one of the newest members of the Miami Dolphins has been an outstanding football player since high school, where he played both linebacker and wide receiver.
At Auburn, Dansby originally started as a strong safety, but eventually moved to linebacker in his sophomore season. In his collegiate career, he recorded over 200 tackles, 10 sacks, and seven forced fumbles.
The Arizona Cardinals selected Dansby in the second round of the 2004 NFL Draft, and he signed with the Miami Dolphins this offseason, holding the largest contract for an inside linebacker until Patrick Willis signed his new deal weeks later.
Last season, as a member of the Cardinals, Dansby made 109 tackles, had one sack, and an interception.
At Nebraska, Ruud was almost as dominating as he is currently in the NFL, as he recorded over 400 tackles while starting in 37 of 50 games.
The Tampa Bay Buccaneers saw his excellence, and selected him in the second round of the 2005 NFL Draft.
Last year, Ruud recorded 142 tackles, forced a fumble, made an interception, and defensed seven passes. At just 27, Ruud has a long career ahead of him.
Williams has often been overlooked, despite being one of the most productive and consistent linebackers in the National Football League.
Williams was selected 17th overall in the 2004 NFL Draft, along with fellow Hurricane linebacker Jonathan Vilma.
As a Bronco, Williams has been very productive, and led the team in tackles during his rookie year. In the 2008 season, Williams made his third linebacker position switch, to middle linebacker, where he plays now.
Williams has thrived at inside linebacker in the Broncos' new 3-4 defense, as displayed by his 2009 statistics of 122 tackles, three forced fumbles, and 3.5 sacks. With fellow inside linebacker, Andra Davis, gone to the Buffalo Bills, Williams will have an increased role, and will be expected to be the leader of the Broncos' defense, in his seventh year in the league.
Lewis has been the most feared linebacker in the National Football League for 14 seasons. The third Miami Hurricane to make this list, Lewis will be enshrined in Canton, Ohio, as soon as he is eligible to make the Hall of Fame.
Lewis has made 11 Pro Bowls, and was named Defensive Player of the Year twice. He was also the quickest player to make 20 sacks and 20 interceptions, by doing so in just 113 games.
At 35 years old, Lewis is still a devastating force on the gridiron. Last season, he made 134 tackles, three sacks, and forced two fumbles.
In his career, Lewis has made over 1,700 tackles, 36.5 sacks, 28 interceptions, and forced 14 fumbles.
The fourth Miami Hurricane to make the list, Beason started his collegiate career as a fullback before making the transition as a redshirt freshman.
Beason made an immediate impact at linebacker, making 187 tackles, 3.5 sacks, and an interception before being drafted 25th overall in the 2007 NFL Draft by the Carolina Panthers.
Beason is an extremely versatile linebacker, as he can play both inside and outside.
Last season, Beason made his second consecutive Pro Bowl after recording 141 tackles, three sacks, three interceptions, a forced fumble, and defensed seven passes.
At just 25 years old, Beason will be making a name for himself for years to come.
Willis is the most dominating middle linebacker currently in the NFL. His combination of explosiveness, tenacity, and athleticism is second to none.
He was drafted 11th overall in the 2007 NFL Draft, after an amazing collegiate career at Mississippi, where he was the winner of both the Dick Butkus and Jack Lambert awards as the nation's top linebacker.
Playing under one of the best middle linebackers of all time in Mike Singletary, Patrick Willis is his protege.
Last season, he recorded 152 tackles, made four sacks, forced three fumbles, made three interceptions, and defensed eight passes.