Our NFC diagrams focus on running and defense. No one runs the ball like the 49ers, and the Packers defense should get its due after an up-and-down season. Don't worry, Aaron Rodgers fans: he also makes an appearance as we break down one of the many reasons the Packers offense is so special.
Green Bay Packers
Let's give the Packers defense a little love. Sure, they gave up almost 5,000 passing yards. But they also recorded 31 interceptions. Dom Capers has not been able to blitz as frequently or as creatively as he did last year because of injuries, but his schemes still force opponents to worry more about pass protection than getting receivers down the field. And Capers is not afraid to use his best players in surprising ways, even if it means dropping Clay Matthews into coverage.
Figure 3 (below) shows the Packers facing the Giants early in the second quarter of Week 13. It's first-and-10. You probably remember this play: a pick-6 by Matthews which turned out to have a major impact on a very close game. Let's take a closer look. Why was Matthews in pass coverage, not chasing Eli Manning? And why didn't Manning see him?
Note that the Giants have six offensive linemen in the game: backup center Jim Cordle (63) is lined up as the left tight end. Right off the bat, the Giants are worried about the blitz. The Packers are not really blitzing: one linebacker is running a stunt behind the three defensive linemen, but four rushers do not a blitz make. Matthews (52) and the other linebacker threaten to rush but drop into soft zones. A deep safety also charges the line in an apparent blitz, but then stops in a middle zone. This is well disguised coverage, and what Manning sees after he play-fakes to Ahmad Bradshaw (44) is nothing like what he expected in his pre-snap read.
Manning turns and tosses to Bradshaw in the flat for a "safe" pass. Matthews is a full seven yards downfield from Bradshaw when Manning cocks to throw, but he reacts instantly, and Matthews is one of the quickest linebackers in the NFL. Manning probably knew that Matthews was lurking nearby; he just thought he could deliver the pass and Bradshaw could get three or four yards out of nothing. As great an individual effort as this was by Matthews, it started with Capers' defense, and the fact that the Giants were so concerned about the blitz that they limited their passing options.
As for the Packers offense, well, we could sit here all day diagramming touchdowns. Let's focus on the unique problems Aaron Rodgers and Jordy Nelson cause for opposing defenses. Rodgers and Nelson have established such excellent timing that a defense can do just about everything right and still give up a big play.
That's no "prevent" defense the Giants are running. They are in tight man coverage, something they would prefer to avoid against the Packers, but they must do something to take away the short pass. The middle linebacker blitzes, and Justin Tuck (91) throws his blocker aside and quickly gets into Rodgers' face. Meanwhile, most of the Packers receivers run short routes. Nelson (87) makes an inside move at the line to get away from Will Blackmon (36), then breaks outside on a fly pattern. Blackmon catches up quickly and is just a half-step behind Nelson.
With Tuck closing for the kill and the passing window open just a crack, a play like this should be a "win" for the Giants. But Rodgers has uncanny accuracy, and Nelson has excellent timing when turning and addressing the ball. This 27 yard catch puts the Packers in field goal range, though another completion two plays later makes it a chip shot.
Why was Blackmon, a nickel defender, covering Nelson? The Packers force those kinds of mismatches on offense. Greg Jennings (85) is their most dangerous all-purpose receiver, so he must be covered by a starting cornerback. Donald Driver (80) draws the other starter, though the Giants' decision to keep the deep safety on Drivers' side of the field is a little curious. Jermichael Finley (88) draws coverage from a safety. There just aren't enough good cornerbacks to go around when facing the Packers, especially for the Giants, who usually can't get through a game without a starter getting hurt.
The Giants did many, many things perfectly against the Packers, and still lost. They must be better than perfect on Sunday. Giants fans can take solace in the fact that they have done that before.
San Francisco 49ers
All inside runs are not created equal. For a team like the Ravens, a run up the middle is an attempt to beat the opponent in old-fashioned trench warfare and set up later aerial strikes. For the Texans, a run up the middle is an exercise in textbook zone-blocking techniques. For the Eagles, a run up the middle is something to watch other teams do while resting on the bench after passing six million times.
For Jim Harbaugh and the 49ers, an inside run is a feat of engineering. No team uses more elaborate blocking schemes on superficially simple plays than the Niners. The intricate blocking patterns make the Niners offense difficult to read before the snap, and they allow some otherwise ordinary personnel on the offensive line to use the element of surprise to win matchups.
All of the color coding should make the play easier to explain. First, look at the thick line representing a block by Delanie Walker (46). Walker is executing a variation on the old-school trap block on Ndamukong Suh (90). When the blockers in front of Suh veer off to take on other assignments, Suh can be counted on to rush straight into the backfield in search of sacks, glory, and future heart-to-heart chats with the commissioner. Walker's job is to crunch him and trap him to the inside as Frank Gore (21) takes a handoff off right tackle. The block does not have to be pretty, because Suh's own momentum is working against him, and Walker nudges him just wide of the play.
Next, check out the blue blocks by guards Mike Iupati (77) and Adam Snyder (68). These are called reach blocks, as both guards engage a defender one full position to the left of the ones they face at the snap. Like Walker, Iupati and Snyder just have to make enough contact to keep those defenders pinned to Gore's left as he hits the hole. The red blocks by center Jonathan Goodwin (59), Joe Staley (74) and Anthony Davis (76) are second-level blocks that knock out linebackers and safeties. There's a lot of criss-crossing going on, and at first glance this play looks like total mayhem. But it creates a huge hole for Gore on the right side. Not only did he gain 55 yards on this run, but he gained 47 yards on a slight variation on the same play earlier in the same game.
The reverse is another tactic Harbaugh often uses to feint defenders out of position and generate big plays in the running game. The Niners have used a wide assortment of reverses and misdirection plays this season, even "tight end around" plays to Walker or Vernon Davis. Their favorite weapon on the reverse is Ted Ginn Jr., one of the league's fastest players.
Ginn takes two quick steps downfield to get the cornerback off his tail, then turns to the backfield and takes a pitch from Hunter. So far, everything is going as planned for the Niners: the right defensive end crashed hard in pursuit of Hunter, so he is in no position to stop Ginn.
The Lions outside linebacker, however, escapes from Staley's block and gets into the backfield. No matter: Alex Smith is happy to block him! Not shown in the diagram, Staley keeps going downfield in search of a safety. Ginn gains 14 yards, partly because of his speed, partly because of play design, and partly because his quarterback is willing to mix it up.
The Saints like to dictate on defense, with Gregg Williams sending blitzers from all directions. Plays like this exploit over-aggressiveness and force defenders to take a more disciplined approach. Once defenders are worried about reverses and trap blocks, Harbaugh can mix in some passing plays, knowing that Smith will have time to get rid of the football.
Mike Tanier writes for NBCSports.com and Rotoworld.com and is a senior writer forFootball Outsiders.