For years, it has been one of the unwavering tenets, arguably the most critical axiom, on which NFL defenses have operated: Stop the run, and you will likely win.
In this the year of the pass, however, the truth in that statement has been hard to find.
Of the top 10 teams in the league versus the run, only half have winning records. The ratio isn't really much better -- six clubs on the plus-side of the ledger -- for the top 10 defenses against the pass.
It might seem like a conundrum, but players around the NFL just figure you've got to play solid enough defense, period, to win.
No edge to stuffing the run or the defending against the pass. Keep people out of the end zone, author a few big plays, and try to fend off the offensive onslaught that has marked the outset of the year.
And count on the offense -- the bottom three teams in the league in overall defense (Buffalo, Oakland, New England) are a cumulative 11-4 -- to score enough points.
The formula for success has changed a bit, at least through five weeks of the 2011 season.
"It used to always start with (stopping) the run," acknowledged Green Bay cornerback Charles Woodson. "That's still essential. I mean, we won (Sunday) night when we tightened up against the run after the first two series, but that's not the only thing anymore. You've got to be sound in everything you do.
"But the way the game is now, there's only so much you can do."
It's notable that three of the four lowest-ranked defenses against the pass feature winning records after five weeks of the season.
The Packers, who are ranked 30th versus the pass, are one of only two undefeated franchises remaining. The Patriots are last in the NFL against the pass, but are 4-1. That would seem to be a recipe for disaster with offenses throwing the ball so much, but it hasn't been.
And a big reason is that offenses have dominated.
Defense was always about the complete game, not just stopping the run. But as Atlanta middle linebacker Curtis Lofton noted a day after his team's Sunday loss to the Packers: "It's probably a little bit 'completer' now. ... And tougher."
Obviously, with rules changes, and the obsessive protection of the quarterback, the game in large part has swung toward the offense.
Eight of the top 10 offensive teams in the league own non-losing records at this juncture of the season. The Philadelphia Eagles rank No. 3 offensively and the Carolina Panthers are fifth, and both have 1-4 record, but they seem to be aberrations.
"The worm has definitely turned," allowed a standout NFC linebacker who spoke only for non-attribution. "You'd like to think it's still about playing great defense, but how many teams can do that anymore? Things seem to have evolved away from the defense. That's a hard pill to swallow, but it's true."
Len Pasquarelli is a Senior NFL Writer for The Sports Xchange. He has covered the NFL for 33 years and is a member of the Pro Football Hall of Fame selection committee. His NFL coverage earned recognition as the winner of the McCann Award for distinguished reporting in 2008.