Being around the NFL for three decades, your palate becomes sensitive to greatness.

Barry Sanders' elusiveness captivates. You never tire of seeing the precision of Jerry Rice in a pass route. Great quarterbacks such as Dan Marino, John Elway, Joe Montana and Brett Favre provide thrills every time they retreat from center. But football is a team sport of violence, and defenses -- great defense -- provide the true essence of football. Power. Dominance. Contact.

	Ray Lewis and the Ravens' defense dominated the Titans in a 26-7 win in Week 4.

Being spoiled by covering the Steel Curtain in Pittsburgh, it's hard to pass platitudes. The 1976 Steelers had the most dominating defense I've ever seen. Terry Bradshaw was hurt, so the Steel Curtain defied any opponent to get first downs against them. The Bears showed that flair in 1985. But the Ravens have reached Steel Curtain status. The Baltimore Ravens challenge the Steelers for the best defense since the merger of the AFL and the NFL. Perhaps the best ever.

Against the Broncos and Titans, the Ravens took defense to that extra level. The Ravens have that rare ability to reach into the chest of an opposing offense, remove its heart, squeeze it and return it to victims like a deflated football. The Broncos pride themselves in running the football. Yet, when they needed a yard against the Ravens, coach Mike Shanahan turned into a run-and-shoot finesse offense and emptied his backfield.

The Titans pride themselves on their ground game. Eddie George has carried his offense to a Super Bowl. Yet, Ravens defenders have stifled and frustrated him. Once he touches a football, the Ravens have it set to slice a defender into the backfield to hit at his feet before George can reach the line of scrimmage. At least once during the game, Ray Lewis tries to make a monster hit that makes George tentative.

Perhaps it's unfair to think that George isn't the same back when playing the Ravens, but it seems that way. Worse, the Ravens believe it, so they are like sharks attacking racks of beef every time he runs.

Say what you want, but the Ravens' defense is better than last year's record-setter. Through four games, they've limited opponents to 48 fewer yards (249 to 201). They've become harder to beat on pass plays (202.5 yards per game to 143.5). They are allowing two less points a game (13.8 to 11.8).

Sunday's game against the Green Bay Packers is a great test because of Favre's uncanny ability to make impromptu completions. Figuring that the Packers didn't run much against the Buccaneers last week, they will try to attack the Ravens with quick, short passes from Favre's arm. Why run? The Ravens allow 57 yards a game. A good punt is longer than that.

The Ravens love this challenge and figure to minimize the Packers. Good luck.

This may be the Ravens' defense at its best. Soon, the salary cap and age will start to eat away at its talent. The Steelers will hold that special place because of longevity. They had breaks. The World League folded before it could grab a few of the defensive starters. With no salary cap and no free agency, the Steelers stayed together through the ends of their careers

So enjoy the Ravens' D. This may be as good as it gets.

Defensive coordinator Marvin Lewis continues to push this defense, which really isn't hard. Ray Lewis, as great as he is as a player, is that much more of a leader. He doesn't want to be beat for a yard, and he carries that pride to practice.

	“	This group works hard. They do things the right way in their preparation and practice habits. The players understand what the work brings. ”
		— Marvin Lewis, Ravens defensive coordinator

"This group works hard. They do things the right way in their preparation and practice habits," Marvin Lewis said. "The players understand what the work brings."

The Steelers' specialty was playing physical football. From the opening kickoff, they pounded teams. Joe Greene and Ernie Holmes punished interior blocking. Cornerback Mel Blount mauled receivers. Linebackers Jack Lambert, Andy Russell and Jack Ham abused ballcarriers. Safeties Glen Edwards and Donnie Shell hit like torpedoes.

The Ravens bring the same punishing style, but they add athleticism and speed.

"Peter Boulware is healthier and running around more," Marvin Lewis said. "Jamie Sharper has played well for two years and keeps getting better. Strong safety Corey Harris is better than what we had. Rod Woodson's having a great season."

The emergence of Harris and Woodson's continued youth have made the Ravens that much better against the pass. It gives the Ravens the equivalent of four cornerbacks for coverage, but four defensive backs who hit like safeties. Cornerbacks Duane Starks and Chris McAlister are turning into the most complete tandem in pro football.

Though the Ravens set records for the fewest points allowed, they still have goals to achieve. Lewis is stressing improvement against third-down conversions. To back up his desires, Lewis talked management into signing Carnell Lake to come in and help in the nickel pass defense.

"We've got two corners who play with confidence, and by adding Carnell, we get another guy who can cover and blitz," Lewis said.

Like the Steelers, the Ravens have the swagger and understand the fundamentals of the game. Tackling is their speciality. It's a skill a lot of great players overlook. Players such as Ham never missed sure tackles.

The Ravens pride themselves in their tackling techniques.

"Tackling is something that doesn't have a lot of time spent on it," Lewis said. "You go back into high school, and you have high school coaches who come in from off campus. So you may not have the time spent on fundamentals. Our coaches do a great job on those fundamentals. In individual drills, we work in groups making sure knees are bent properly to get players in position for tackles. We preach about finishing the play. You have to have tough skin to be a player in this defense, but you don't want to come into the meeting room and be critiqued for poor tackling."

No, the Ravens' defense probably won't have the longevity of greatness achieved by the Steelers. The Ravens have carried their excellence into their third season. They survived last year's scoring drought. They survived free agency during the offseason. They are better and they are peaking.

Smuggly, I used to think Steelers when I thought defensive excellence. Nevermore. The Ravens are in that class, too.

John Clayton is a senior NFL writer for ESPN.com.