Football is a violent sport—there's no debating that.
We see opposing players line up across from each other, with blood stains on their jerseys, ready to simply beat the ever-loving daylights out of each other.
In order to play the game of football, you have to be tough. There's no way around it.
In that spirit, let's take a look at the 25 toughest teams in NFL history.
The 1963 Chicago Bears went on to finish with an 11-1-2 record on their way to an NFL Championship.
The Bears defense was the heart of their game as they allowed just 10.3 points per game and had a takeaway/giveaway differential of an incredible +29.
The '63 Bears were led by defensive players Doug Atkins, Ed O'Bradovich, Bill George and Larry Morris.
The 1994 San Diego Chargers might have not won the Super Bowl and might not have had the greatest stats, but they were such a violent team that was always looking to knock off the opposing players' heads.
This team was led by NFL great Junior Seau and Leslie O'Neal.
The '94 Chargers always put on a beating week-in and week-out, no matter if it was a win or a loss.
If Jack Youngblood isn't a tough name, then I don't know what it is.
All I know is that I would fear a guy with the last name of "Youngblood."
Youngblood led the 1975 Los Angeles Rams to one of the greatest defensive performances in NFL history. They allowed just 9.6 points per game while physically dominating teams on their way to the NFC title game, which they ultimately lost to the Dallas Cowboys.
To continue on with the great year of 1975, the Pittsburgh Steelers were simply a nasty team to play against.
The '75 Steelers were led by Rocky Bleier, Franco Harris, L.C. Greenwood, Joe Greene, Jack Ham, Jack Lambert, Mel Blount and Mike Wagner—who were all very intimidating players.
The Steelers went on to record a solid 12-2 record while allowing just 11.6 points per game and running the ball down opposing defense's throats with an impressive 2,633 total rushing yards.
The 1973 Miami Dolphins went on to post a 12-2 record on their way to a victory in Super Bowl VIII.
The '73 Dolphins were a very defensive team and were known as the "No Name" defense.
This group of players was led by the incredible play of defensive end Bill Stanfill, who set a Miami Dolphins record with a stellar 18.5 sacks in the regular season.
Mean Joe Greene led the 1974 Pittsburgh Steelers to a solid 10-3-1 regular season record and ultimately won Super Bowl IX.
This team had six Pro Bowlers on the roster and was loaded defensively. This was the first Steelers team to win a Super Bowl and was the start of the "Steel Curtain" defense.
The '74 Steelers were simply tough in all phases of the game.
Look into the eyes of Jack Lambert—is that someone that you want to mess with? Absolutely not.
How about Jack Ham, Franco Harris, Joe Greene or Mel Blount? I didn't think so.
The Super Bowl XIII champions were a group of players that you did not want to mess with.
What makes the 1972 Miami Dolphins so tough?
One word: Perfection.
The '72 Dolphins are the only team in NFL history to record a perfect season. That's tough if you ask me.
Hank Stram's "triple stack" defense was the major reason behind the 1969 Kansas City Chiefs' success.
The '69 Chiefs were led by defensive players Buck Buchanan, Bobby Bell and Willie Lanier—and they're all Hall of Fame players.
In the team's three playoff games on their way to a Super Bowl victory over the Minnesota Vikings, the Chiefs allowed a mere 20 total points.
How insane is that?
All we have to know about the 1964 Cleveland Browns is that they pounded away with the running game led by Jim Brown, and that Brown was ultimately much stronger and bigger than his own offensive linemen.
If you ask me, that's pretty damn tough.
The '64 Browns went 10-3-1 and went on to win the NFL Championship.
The 1962 Green Bay Packers are not only one of the greatest Packer teams in history—they're also one of the greatest defenses since they were such a violent group of players.
The '62 Packers had Hall of Famers Willie Davis, Henry Jordan, Ray Nitschke, Herb Adderley and Willie Wood on the defensive side of the ball.
Green Bay allowed just 10.8 points per game; moving the ball against this group was extremely difficult.
The "Gritz Blitz defense."
The 1977 Atlanta Falcons may have only gone 7-7, but they had one of the greatest defenses in NFL history as they allowed an NFL-record 9.2 points per game.
The '77 Falcons were as tough as nails as they blitzed nearly every single play and put fear in opposing quarterbacks' eyes.
The 2003 New England Patriots—What can I say about this group of players?
For starters, this was the second Super Bowl-winning team in the New England dynasty as they took out the Carolina Panthers in Super Bowl XXXVIII.
The '03 Patriots defense was led by Rodney Harrison, Tedy Bruschi, Ty Law, Roman Phifer, Willie McGinest, Richard Seymour, Bobby Hamilton, Ted Washington and Mike Vrabel as they led the league with an impressive 14.9 points allowed per game.
But what makes this team so special? They represent the start of a remarkable winning streak.
To continue on the last slide, the 2004 New England Patriots, which had almost the identical roster of the year prior, went on to win 21 straight games.
I don't think too many people realize how remarkable that is in today's NFL, due to the parity of the league.
The '04 Patriots went on to win the Super Bowl, but what separates them from the '03 Patriots?
One player: Corey Dillon.
Dillon was a bone-bruising running back that added a whole new dimension to New England's offensive attack.
"The Purple People Eaters."
That nickname alone shows how tough the 1971 Minnesota Vikings were.
In the '71 season, the Vikings allowed just 9.9 points per game and held the motto of "meet at the quarterback."
How awesome is that?
All in all, this team was so tough that Alan Page became the first-ever defensive player to be named NFL MVP.
There is no question that the Pittsburgh Steeler defenses of the 1970s were legendary, but the 1976 version is certainly the best. In fact, many believe that this is the greatest defense ever to play football.
The '76 Steelers posted five shutout wins but failed to make it to the Super Bowl as they lost the AFC Championship against the Oakland Raiders—but they are still one of the toughest group of players ever to play the game.
Quite frankly, the 1984 San Francisco 49ers could very well be the greatest team in NFL history—they're without a doubt one of the toughest.
The '84 49ers posted an incredible 15-1 record on their way to a victory in Super Bowl XIX.
The team was led by hard-nosed defensive players Ronnie Lott, Keena Turner, Carlton Williamson and Manu Tuiasosopo.
The 1988 San Francisco 49ers are quite arguably one of the most underrated teams in NFL history, since they're overshadowed by all the great teams in the San Francisco dynasty.
The 49ers might have posted only a 10-6 record, but they did go on to win the Super Bowl as they were tough on both sides of the ball thanks to players Joe Montana, Roger Craig, Tom Rathman, Ronnie Lott, Bill Romanowski and Charles Haley.
You may think of the 2007 New England Patriots being a finesse offense because they set several passing records, but they're tough in two different areas.
For starters, this team posted a perfect 16-0 regular-season record—which means that the pressure was at its max game-in and game-out. That definitely takes a lot of mental toughness.
Also, this team was pretty tough on the defensive side of the ball led by Rodney Harrison, Tedy Bruschi, Richard Seymour, Mike Vrabel and Junior Seau.
The 2000 Baltimore Ravens were the toughest team since 1990.
The Ravens were led by defensive maniacs Ray Lewis and Rod Woodson. On the offensive side of the ball, they pounded away with the ground game thanks to the powerful legs of Jamal Lewis.
All in all, you did not want to mess with the Super Bowl XXXV champion Baltimore Ravens.
Lawrence Taylor, Harry Carson and Jim Burt—Do I need to say much more?
The 1986 New York Giants were one of the toughest teams ever to play the game. They were a violent defensive team that held opposing teams to just 14.8 points per game while going 14-2 and winning Super Bowl XXI.
The 1976 Oakland Raiders were simply as tough as nails. There's no better way of putting it.
The '76 Raiders were led by Jack Tatum, Ted Hendricks, Art Shell, Gene Upshaw, Dave Casper and Cliff Branch as they ultimately went on to post a stellar 13-1 record on their way to a Super Bowl victory against the Minnesota Vikings.
This is an old-timer for everyone out there, but the Canton Bulldogs are the current holders for the longest winning streak in NFL history; they won 25 straight games from 1921 until 1923.
The Bulldogs played in an era of football where the talent may not have been the best but toughness was. In fact, I think that it's safe to say that toughness was valued far more than talent was back in the '20s.
Aside from the Super Bowl Shuffle, the 1985 Chicago Bears are the toughest team in NFL history.
The Bears were incredibly tough on the defensive side of the ball. They were led by Mike Singletary and William "Refrigerator" Perry. The '85 Bears only gave up 198 total points while posting a stellar 15-1 record on their way to winning the Super Bowl.
If you were fortunate enough to see this team play, then it should be pretty evident that they're not only the greatest defense in NFL history, but they're also the toughest team ever to play football.