Thursday night, we saw somewhat of a rare occurrence – the Packers won a game, not because of Aaron Rodgers, but because of a dominating defensive performance. They held the Bears to just 3 points and 254 total yards. Along the way, Green Bay notched 5 sacks, forced a critical 4^th quarter turnover, and held the Bears to just 3 third-down conversions on 15 tries. Right from the first drive, Defensive Coordinator Mike Pettine’s approach gave Chicago trouble.

A common theme throughout the night was the Packers’ insistence on showing double-A-gap pressure at the snap. Sometimes they’d bring those A-gap defenders. Sometimes they’d drop out and other defenders would blitz off the edge. Most of the time, the Bears had trouble responding.

The below play was a 3^rd-and-9 on Chicago’s first drive of the game. You can see the two Green Bay defenders aligned in the A gaps.

Martinez ended up coming, while Smith dropped out. Clearly there was a miscommunication here because defenders aligned over the center are generally not given free paths to the quarterback as a rule. It looked like right guard Kyle Long was supposed to slide to his left to help out with the double-A gap look.

Communication on the offensive line is vital in handling double-A-gap pressure. Chicago had trouble with this in the early going. In the 2^nd quarter, it led to near disaster. This was another 3^rd-and-9. Again, look at the two defenders in the A-gaps.

There are really two main ways to protect against this look. Keeping defenders out of the middle is the key component here. The protection could be man-based, where the 5 offensive linemen are responsible for the 4 “down” linemen and the identified “Mike” linebacker in the A-gap. The running back would then be responsible for the other linebacker in the A-gap. This is all illustrated below.

The other option is to use a slide protection with each lineman blocking the gap to the same side. This ensures that the biggest offensive linemen are protecting against pressure up the middle. The only issue here is that this puts the running back against an edge rusher, which is a bigger mismatch than the running back against a middle linebacker. This protection is illustrated below.

Teams can also use combinations of these two protections based on alignment (slide to one side, man to the other).

On this particular play, Trubisky went with a hard count to see who was coming, which was a smart move. Both A-gap defenders appeared to be blitzing. If you go back and watch the game broadcast, you can hear the word “Gator” being yelled on the offensive line after the hard count. This is just our guess, but the Bears were likely switching from a man-based protection to a slide. Perhaps “Gator” was code for using a slide protection, with the “G” in Gator signaling for each lineman to block the gap to the same side.

Unfortunately for the Bears, it appeared that running back Mike Davis and right tackle Bobby Massie did not get the call. They both appeared to block based on the initial man-based protection. At the snap, Davis looked inside towards the A-gaps initially, and Massie was ready to block the edge rusher, assuming the defensive tackle was being taken by the right guard as he would be in a man-based protection.

This left defensive tackle Kenny Clark with what looked to be an unimpeded path to the quarterback. Not what you want.

Mike Davis did a hell of a job recovering at the last second to get a piece of Clark. However, Trubisky had to be unsettled seeing a 300-lb defensive tackle getting a clear path to him right at the snap. Between that and a collapsing pocket to the left, the play was disrupted, and Trubisky had to move. He then forced an ill-advised pass that should have been intercepted.

This is the chaos that double-A-gap looks can create.

Trubisky made several other bad decisions on Thursday Night. Whether it was the rust from a lack of snaps in preseason or the Packers’ pass rush, he did not look comfortable. He did not consistently work through his progressions. He stared down his receivers, like on this near interception below.

Here, Trubisky kept his eyes focused on wide receiver Allen Robinson (#12) in the slot to his left. The safety, rookie Darnell Savage, was able to read Trubisky’s eyes and make a play on the ball as a result.

Trubisky’s biggest mistake came in the 4^th quarter with the Bears threatening to tie the game. Once again, he stared down his receiver and did not work through his reads to find the open man.

Watch the deep safety, Adrian Amos, in the middle of the field below. He followed Trubisky’s eyes right from the snap. He was not concerned at all that Trubisky was possibly looking left before coming back to the other side. This enabled him to get to the ball quickly.

In fairness to Trubisky, there was no other route to hold the deep safety in the middle of the field. Still, this was a high-low read to the left. And you can see below that Tarik Cohen was open underneath on an in-and-out route (sometimes called a burger route or a whip route).

This was a 3^rd-and-10 with the Bears trailing by 7 and two minutes remaining, meaning it was 4-down territory. A completion to Cohen there likely gets you the first down. If it doesn’t, it at least creates a 4^th-and-manageable situation. This was just an all-around bad play by Trubisky, and a sign that he was not reading or seeing the field clearly.

We’ve written about this before, but when quarterbacks don’t have time, they don’t believe they will have the opportunity to work through their reads from the pocket. This leads to some quarterbacks committing to a receiver based on the pre-snap look and therefore staring him down as he waits for the receiver to get open. This looked to be what happened to Trubisky on several plays against the Packers.

Trubisky has, to date, been an inconsistent quarterback from the pocket. Coming into this game, we thought the Packers had to do a better job on 3^rd down of not letting him get out of the pocket and use his legs. Based on Tramon Williams’ post-game comments, it seems like Green Bay was thinking the same thing. From the Bears perspective, Trubisky has to get better working through his reads from the pocket. Otherwise, inconsistency will continue to plague his game.

With that being said, Aaron Rodgers seemed very excited about his defense after the game. He finally has good reason to be. Not only does Defensive Coordinator Mike Pettine employ a complex scheme that is difficult to decipher, the Packers added a lot of talent this offseason. And most of that talent was on full display Thursday Night.

You saw safety Adrian Amos make the biggest play of the game with his interception above. Outside linebackers Preston Smith and Za’Darius Smith made several big plays as well. Za’Darius aligned inside often, enabling him to use his athleticism to take advantage of outmatched guards. You can see the play he made below on the 2^nd to last defensive snap of the game.

That quick penetration impacted Trubisky’s follow-through and the throw as a result.

Preston Smith got the sack on the very next play, sealing the game. This one came off of a stunt, one of several that the two smiths executed successfully on Thursday Night.

First round draft pick Darnell Savage made several plays at safety as well, including the near interception we highlighted earlier.

Yes, it’s easy to overreact in Week 1. But if this Packers Defense is actually for real, and they certainly looked to be against the Bears, Green Bay could be a serious contender once again.