However, the soon-to-be 32-year-old linebacker's tackling numbers don't tell the whole story.
Although Barnett was relatively active, making a few splash plays per game, he was a major liability in Buffalo's defense that allowed five yards per carry on the season and gave up the most touchdowns per drive, according to Football Outsiders.
Now that he's on the free-agent market, what does Barnett still have to offer NFL teams?
First and foremost, Barnett is a fiery competitor. He won't have a Ray Lewis-type motivational impact on a defense, but he won't be follower either.
Some teams want a passionate leader in their linebacking corps.
In all likelihood, Barnett will not be acquired to be the "leader" of a defense or a linebacking unit, but his spirited demeanor should be welcomed even in a diminished role.
The former Green Bay Packer excels when attacking the offensive line and is quick to trust his instincts immediately following the snap.
The only problem is his instincts are occasionally incorrect and he can get overzealous when looking to track down a running back.
When that happens, Barnett plays into the offensive line's hands and often takes bad angles, which open huge holes in the defense.
When Barnett does find the correct gap, he is a relatively sure tackler. However, if there's any lead blocker, he doesn't have the athleticism to get around the block nor the ability to shed it and make a tackle.
From sideline to sideline, Barnett leaves a lot to be desired. Most linebackers have trouble beating a running back to the corner, but Barnett is typically more than a few steps behind runners attempting to get to the perimeter and his lack of speed doesn't allow him to track plays from behind very often.
In coverage, Barnett struggles mightily.
According to ProFootballFocus.com (subscription required), Barnett allowed a QB rating of 129.8 on passes into his coverage in 2012, the highest among all 4-3 outside linebackers.
He simply isn't fast enough to stay with slot receivers or today's more physically gifted tight ends.
At this point of his career, Barnett would be best suited as a 3-4 inside linebacker, mainly playing downhill, but he would have to play next to a true thumbing inside linebacker to be productive.
When comparing the two, Barnett is much more capable as a run defender than he is as a cover man and he could be effective in the 3-4 on the inside.
Do you want your team to sign Nick Barnett?
What's encouraging about Barnett is that he didn't suffer any injury setbacks during his two-year stint in Buffalo after tearing a knee ligament in Green Bay during the 2010 season.
If the Arizona Cardinals don't re-sign Paris Lenon, Barnett and Daryl Washington would make an interesting pairing—especially with Washington being one of the most complete linebackers in the league.
With Bart Scott gone in New York, Barnett and David Harris could benefit each other in the Jets' 3-4 system.
In conclusion, Barnett is clearly in the twilight of his career, but is quick to diagnose plays, tackles well and is a decent blitzer.
Playing next to a premier linebacker, Barnett could be serviceable in a stopgap role.