One of my readers wrote to me the other day, and wanted to know why we don’t see the old Bears' “46” defense anymore. As I started to reply to him, I thought that this would make for an interesting article for everyone to read.
Here is a bit of trivia before we get into how the 46 defense worked, and why we don’t see it much anymore: The name "46" Defense didn’t come from the alignment of the players on defense; it came from free safety Doug Plank, who wore jersey number 46, and was a hybrid free safety slash linebacker in Buddy Ryan’s system.
The basic idea of the 46 defense is that the defensive tackle lines up over the center, the other defensive tackle lines up over the right guard, and a defensive end lines up over the left guard. No defenders are placed over the offensive tackles, instead a defensive end is placed to the outside shoulder of the left tackle and old number “46”, who is a cross between a linebacker and a free safety, is placed to the outside shoulder of the right tackle.
Lined up on the outside of the defensive end, and the 46, you have two outside linebackers, giving you a seven man front, with the middle linebacker lined up right behind the defensive tackle, who is playing a 0 technique -- meaning he is lined up directly in front of the center.
In the secondary, you have two corners lined up on the outside receivers playing man, and the free safety playing zone in the deep middle.
This defense was so successful because of their ability to collapse the line, shutting down the run, and sacking the quarterback before he could get a pass off.
In 1984 this system produced 72 quarterback sacks, and in 1985, when they made their Super Bowl run, the defense had a six game streak, where, on average they only gave up 4.5 points per game, and during the playoffs only allowed 10 points over three games. This defense paved the way to their winning Super Bowl XX.
Buddy Ryan had great success with this system not only in Chicago, but also in Philadelphia. In Chicago, he had Dan Hampton lined up over center, and in Philadelphia, the defensive tackle over the center was the late, great, Reggie White.
Both of these men were so strong, and such excellent pass rushers, that they could collapse the offensive pocket by themselves, even when they were taking on two blockers. This allowed the rest of the defense to come crashing in on the the QB so quickly that he had no time to get the ball off.
Interestingly, Jeff Fisher, who played for Buddy Ryan, adopted the 46 defense for a while, as head coach of the Tennessee Oilers, who are now known as the Tennessee Titans.
The reason the 46 defense fell out of favor is that when it came to pass coverage, you only had three defensive backs to protect the whole field. It was designed to leave the cornerbacks in man coverage 90 percent of the time, while the FS was left on an island playing a deep zone. Not only did he have to protect the middle of the field against the deep pass, he also had to assist the two corner backs in pass coverage.
Sure, you can drop one or two linebackers into zone coverage, but this usually leads to mismatches when teams spread the defense out with more than two wide receivers, or match up a tight end against a linebacker.
The bottom line is, you’re trying to defend the pass with only three defensive backs. As the league became more and more pass happy, and the rules changed to favor the offense and the passing game, this system became less and less effective.
On top of that, for the 46 defense to really be successful, you need a Dan Hampton or Reggie White type lined up over the center. Those kind of guys are hard to come by. If you don’t have someone like that on your team, then your ability to collapse the pocket, before the quarterback can get the pass off, is greatly diminished.
Still, the 46 defense has its place in today’s game. It’s very effective when teams use compressed sets, where they line up with two backs in the backfield, and two or three tight ends (what's called a 22- or 23-personnel grouping respectively). The reason being, is that the 46 defense was designed to work against teams who use a lot of I formations and other sets where the defense is condensed. It’s just not meant to be a base defense in today’s game, where more and more teams use some version of the spread offense.
The 46 defense has not been lost, nor forgotten, just modified, and used more judiciously now, than it was 23 years ago.