DK Note: From the archives -- I wrote and published this article about the Seahawks' pass defense back on January 29th, during the week before the Super Bowl. Whether you missed it the first time around or just need a refresher, hopefully you enjoy it.

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The NFL is a passing league. It's stated so often these days that it's almost a cliche.

Still, Peyton Manning's regular season - the best passing season in NFL history - fully represents this trend. The 16 year veteran shattered the all-time passing touchdowns record and easily broke the passing yards record, and led his team to a 13-3 record before breezing through the Playoffs and into the Super Bowl. Past Manning's year, seven of the top ten passing seasons by quarterbacks in NFL history have happened in the last four years. Only four of the top 20 passing seasons on record happened prior to the 2000 season. There are still some teams playing old-school football on offense, but if you want to succeed in the modern NFL, if you want to be able to beat the top quarterbacks in this league, you better be able to defend the pass.

Only two teams ran the ball more than they threw it this year, and 2013 was the highest scoring NFL season of all time (both total points and average team points per game). In this historically pass happy and high-scoring season, Pete Carroll's Seahawks led the NFL in interceptions while giving up the fewest points, the fewest total passing yards, the lowest average yards per pass, and 2nd-fewest passing touchdowns.

It's a pass defense that, after accounting for era, noted statistics guru Chase Stuart called 'the second best since at least 1970."

Carrollosophy:

To understand Seattle's elite pass defense, it makes sense to look at Pete Carroll's football philosophy.

Seahawks "Defensive Passing Game Coordinator" Rocky Seto gave a presentation in March 2008 at USC about secondary play (Seto was previously the Defensive Coordinator at USC as well). Seto walked on as a linebacker at USC and has worked for Carroll his entire coaching career, so I generally just look at Seto as a Pete Carroll spokesperson. In that presentation (which is no longer online but similarly styled reports can be found at TrojanFootballAnalysis) he broke down the Pete Carroll philosophy for defense:

Three main principles of secondary play:

#1 Eliminate the big play

#2 Out hit the opponent on all plays

#3 Get the ball -- either strip the ball or make the interception when in position.

Notes from Seto's explanation of those three points do a great job of really defining the defensive principles that Pete Carroll has developed over three decades of coaching, but has fine-tuned at USC and now in Seattle.

#1 Eliminate the big play

In summary, Carroll believes that giving up big plays -- in either the run game or the pass game - will ultimately cost you the game. While every scheme, man, zone, or a combination of both, has weak points, Carroll is most concerned about protecting the deep middle of the field against the explosive pass. That's the first thing he will teach to new safeties, and it's a statistic that Carroll and his staff monitors closely. It's a specific focus in their program.

As Seto's presentation declares,

Sorry math- and stat-phobes, USC coaches both track and hang their hat on this notion and it is the #1 base principle for secondary play. USC annually leads the Pac-10 in not allowing big pass plays on defense.

The results bear this out for Carroll's NFL team: In 2012, the Seahawks gave up five passes of 40+ yards (4th in the NFL) and 40 of 20+ yards (6th in the NFL). In 2013, the numbers were better, as Seattle gave up an NFL-low three pass plays of 40+ yards and an NFL-low 30 pass plays 20+ yards.

Carroll's philosophy in action.

Speaking to Seto/Carroll's specific focus on taking away the deep middle of the field, consider this: In 2012, opposing teams only attempted 15 passes to the deep middle -- best in the NFL. In 2013, teams attempted a mere 8 passes to the deep middle -- even more best in the NFL.

Carroll's philosophy in action.

#2 Out hit the opponent on all plays

This philosophy of being physical and punishing opposing offenses ties in with the 'take away the big play' mantra. If you're taking away everything deep, that will open up options for teams underneath. Apart from the actual hits, forcing opposing offenses to string together a series of 9, 10, 11 plays in any given drive increases the odds forcing a mistake or a punt. Carroll's medicine for giving up more shorter underneath gains is to make receivers, tight ends, and running backs really feel the defense each time they catch it.

Seto's presentation notes:

When [the defender cannot arrive in time] to disrupt the pass, the emphasis then switches to delivering good clean hard hits on the wide receiver. Multiple film examples were shown where completed passes were rendered incomplete by the quality of the hit put on by the defensive back. Also, even when the ball is completed, the hit put on the receiver has the psychological effect of making them tentative in the future.

As stated, quarterbacks - and in the Super Bowl's case, Peyton Manning -- are going to inevitably complete passes against the defense. The idea for Carroll then is that if you physically punish your opponent and hit them hard when they catch the ball, there's a better chance that you can dislodge the football (which is what happened to Vernon Davis above) or even better, make the receiver tentative when going for the football in the first place (as you can see with Michael Crabtree on a key third down late in the NFC Championship Game below):

This is what Deion Sanders refers to as a "business decision."

Carroll's philosophy in action.

#3 Get the ball -- either strip the ball or make the interception when in position.

Carroll's teams spend extraordinary amounts of time, particularly for an NFL team, running basic drills. One focus is on drills that make the act of forcing and recovering fumbles second nature.

As the Seto presentation noted,

USC practices daily drills for DB's in individual practice periods with both cornerbacks and safeties breaking on different balls. Coaches throw hitches, slants, outs, fades, seams, post, corner, and go routes. One DB tries to catch the ball one tries to bat it away or make the interception. Much attention is put upon footwork, hands, and hip motion and direction in turning. Stripping balls from receivers is emphasized as well in drill and in actual scrimmages. They key coaching point is to get the hand onto the tip of the ball and find a way to rip it out. This has to be emphasized and practiced or it will not just happen. Dislodging balls from behind is also practices as well. When two players tackle a receiver if possible one should hold him up and pin his arms while the other strips the ball away. This takes team work and not just going for the big hit.

I've seen this at Seahawk training camp sessions so it's a tenet that Carroll and Seto have brought to Seattle. Again, it's instilling a second nature into players to strip and punch at the football. From last Sunday:

The Seahawks forced 17 fumbles in 2013 (5th in NFL), intercepted 28 passes (1st in NFL) and were first in the NFL in takeaways as a defense.

Carroll's philosophy in action.

The Xs & Os:

"We play man-to-man or Cover-3, not much more than that. It's not a secret." - Kam Chancellor, January 2013

The players:

It's tough to summarize any NFL defense in general terms, but the Seahawks' defense is certainly characterized by a three-deep look, typically either Cover-3 or Cover-1 (man-free).

The main characters in the Legion of Boom are All Pro CB Richard Sherman, All Pro FS Earl Thomas, 2nd Team All Pro SS Kam Chancellor, and up-and-coming CB Byron Maxwell. Walter Thurmond mans the slot as the nickel defensive back, and he'll surely play a big role in Super Bowl XLVIII.

You've probably heard Sherman, Thomas, and Chancellor, and maybe even Thurmond, but if you haven't heard of the Maxwell, here's what you should know:

Byron Maxwell in coverage since Wk 13: 30 targets, 10 completions, 1 TD, 4 INT, 22.5 QB rating allowed. #Seahawks — Pete Damilatis (@PFF_Pete) January 25, 2014

Even the TD that Byron Maxwell did give up in Wk 16 took a phenomenal catch by Michael Floyd: pic.twitter.com/wGcT5SHYld — Pete Damilatis (@PFF_Pete) January 25, 2014

Maxwell, Seattle's fourth string cornerback behind starter Brandon Browner and backup Walter Thurmond, came on in relief after Thurmond was suspended and Browner was injured (then suspended), and he's locked down the spot.

The Scheme:

Over at the mothership, SBNation.com/NFL, I broke down Seattle's Cover-3, man-free scheme in more detail, so head over there for the complementary piece to this article....