By Dan Durkin—

(CBS) In case you missed it, Green Bay quarterback Aaron Rodgers is good at football.

Since becoming the full-time starter in 2008, Rodgers has played against every team in the league and beaten all of them except the Cincinnati Bengals, Kansas City Chiefs and Seattle Seahawks.

Locally, Bears fans know Rodgers’ dominance all too well. In games he’s started and finished against Chicago, his record is a gaudy 12-2, and three of the eight highest-passer ratings of his career came in games against the Bears — 151.2, 145.8 and 142.7.

When you sift through Rodgers’ game logs, one fact stands out. From 2012 through 2014, he went 0-4 against the San Francisco 49ers — and new Bears defensive coordinator Vic Fangio was calling the shots for the 49ers in each of those games.

Obviously, it takes a complete team effort to beat the Packers. In three of the four games, the 49ers won the time of possession and turnover battles and had fewer penalties. But Fangio’s game-planning also played a big role in the four-game sweep.

After reviewing each of the games in detail, one aspect stood out to me as being crucial to the 49ers’ defensive success — Fangio’s trust in stopping Green Bay’s run game without safety help.

That may sound like an insignificant detail, but it’s not.

By trusting his down linemen and linebackers alone — which means playing a seven-man box in base or a six-man box in nickel — Fangio was able to stay back in a two-deep safety shell to keep a top on the defense, which enabled him to mix and roll coverage to protect his nickel backs and linebackers, shrink downfield passing lanes, as well as tempt the Packers to run the ball from spread sets.

Let’s step inside the film room to take a closer look.

In this cutup, the Packers are in “11” personnel with Eddie Lacy in a gun right set, with a Y tight end (on the defense’s left) creating a four-man blocking surface to the offense’s right side.

The 49ers respond with nickel personnel in a 3-3-5 alignment with (from left to right) outside linebacker Ahmad Brooks in a three-point stance nine-technique, defensive tackles Ray McDonald and Justin Smith in two-techniques, outside linebacker Aldon Smith in a two-point stance wide five-technique, inside linebacker NaVarro Bowman as the “Jack” backer stacked in a 20-technique and Patrick Willis as the “Mike” backer on the bubble in a 50-technique, forming a six-man box.

With the Packers set to run a gap scheme to the offense’s strength (the right side of the formation), this play comes down to McDonald’s ability to win the A-gap off the snap and force a double team from the center.

By forcing the double team, the numbers shift to the 49ers’ advantage, as there are now three tacklers matched up against two blockers and a ball-carrier. The 49ers’ run integrity is strong, as Brooks sets the edge and owns the D-gap, while Bowman fits the B-gap and Willis the C-gap.

Lacy has no lane to get on track and is dropped at the line of scrimmage.

Plays like this were commonplace in each game. The Packers were held to 63 or fewer rushing yards in half of the games.

By being able to stop the run without having to drop a safety down into the box, Fangio and defensive backs coach Ed Donatell (also now with the Bears in the same capacity) could mix and match their coverages, showing some Cover-1, Cover-2, Cover-4 and Cover-6 looks as well as some mixed coverage schemes.

The 49ers’ mixed coverage consisted of press-man coverage by the outside and slot cornerbacks with the strong safety dropping down and joining the inside linebackers to form a a three-man underneath matchup zone, with a single-high safety lurking over the top.

Such looks challenged the releases of Packers’ receivers off the snap, disrupting their timing enough to allow the four-man rush packages to get Rodgers off his launch point. Furthermore, the matchup zone underneath took away inside lanes and limited checkdown options by bracketing inside receivers Randall Cobb and Jordy Nelson, whom Green Bay is fond of deploying from the slot on option routes.

But the 49ers’ most common and successful coverage choice against Rodgers was their two-man look, which is a two-deep shell with five underneath defenders manned up.





The success of the 49ers’ two-man coverage calls was predicated on physical jams at the line of scrimmage by outside and slot cornerbacks followed by tight trail-man technique in the route, as well as the pass rush’s ability to get home with four rushers.

You can’t stop Rodgers. You can only hope to contain him by forcing him to throw into tighter windows down the field and decrease the percentages, which Fangio did.

Fangio’s presence alone doesn’t guarantee success against Rodgers for the Bears. In fact, it calls out what the Bears lack, which is stout run defenders along their defensive front who can hold up on their own without the need of safety help. Bears fans need to give Fangio and the front office time to accumulate more talent along the defensive line and the inside linebacking corps, then hope that he’ll be able to deploy similarly successful game plans against Rodgers in the coming seasons for Chicago.

Dan Durkin covers the Bears for CBSChicago.com and is a frequent contributor to 670 The Score. Follow him on Twitter at @djdurkin.