Steelers film room: Did Colts expose a weakness in Mike Tomlin's zone defense?

Christopher Carter / Pittsburgh Post-Gazette

Do the Steelers have a defensive scheme problem?

That’s a question naturally posed after Sunday’s 27-24 loss to the Colts. The Steelers were the NFL’s top defense in points allowed and yards allowed, but now sit at second in scoring and fourth in total yards after Colts quarterbacks Anthony Richardson and Joe Flacco combined to complete 19 of 30 passes for 239 yards and two touchdowns with no interceptions.

So what led to the Colts’ passing game being so efficient? A closer look at what happened in the Steelers’ coverage packages shows where the defense went wrong and allowed open players to attack the soft spots of the Steelers’ zone defense. That’s where Mike Tomlin, Teryl Austin and the Steelers’ defensive leaders will need to focus on to avoid teams copying the Colts’ plan of attack in future games with exploitative success.

Scary numbers

Sports Information Systems charts the Steelers as giving up 51 receptions on 57 passes for 591 yards and two touchdowns with three interceptions when opponents have targeted the middle of the field. (For SIS, this includes what they label as middle, middle-left, and middle-right.) Those 591 yards are fifth-most in the NFL, although the Steelers’ pass defense ranks eighth with just 698 passing yards allowed total.

Out of those 591 yards, the Steelers allowed 158 of them against the Colts on Sunday. But was it more of a result of the Steelers’ zone-heavy scheme, or miscommunications and execution on the field?

When Tomlin was asked during his Tuesday press conference, he wasn’t overly concerned about the Steelers’ pass defense in the middle of the field against the Colts.

“They hit some plays in the middle portions of the field, but I didn’t think that defined the outcome of the game,” Tomlin said. “Offenses are going to hit plays, get yards and maybe even score points. But I don’t know that it’s registering enough for me right now to address it as a matter.”

That seems odd from a surface level view of the numbers, but maybe Tomlin has a point.

The Steelers’ defense had largely been fine, even with teams passing to the middle part of the field in their previous three games. Against the Falcons, Broncos and Chargers, the Steelers allowed 435 passing yards to the middle of the field — an average of 145 yards, close to the 158 allowed to the Colts.

But the biggest difference was that the Steelers didn’t allow a single touchdown while also registering three interceptions in those contests — then they allowed two touchdowns with no interceptions against the Colts.

So, what does the tape tell us?

Communication breakdowns

The Steelers’ two passing touchdowns allowed in this game doubled the two they’d allowed in their previous three contests combined. But all four have one thing in common — communication breakdowns.

Against the Falcons, slot cornerback Beanie Bishop didn’t float back towards the end zone that allowed tight end Kyle Pitts to get a wide-open touchdown. Against the Chargers, cornerback Joey Porter Jr. was in underneath zone coverage while safety Minkah Fitzpatrick was late getting behind him on a go-route from receiver Quentin Johnson for another wide-open score.

On Sunday, similar problems happened on both the Colts’ passing touchdowns.

The first score through the air was an obvious case of miscommunication, when Flacco threw to receiver Josh Downs on an in-breaking route that was open for a 4-yard touchdown. The confusion came from Porter, who appeared to be assigned to cover Downs on the play but backed off into a zone covering the flat.

However, Bishop was in man coverage covering an out route to that part of the field, which put two Steelers defenders in one place, leaving Downs plenty of space to work for the score. After the play, you could see linebacker Patrick Queen’s dismay toward Porter.

It’s possible Bishop was the player who made the error and Porter was supposed to remain in the flat. But Queen’s ire after the play paints seemingly paints a picture that Porter was at fault.

On defense, the simplest of lapses by one player can open up the opportunity for an offense to strike for a big play. That was the circumstance on both of the Colts’ touchdown passes. Flacco’s second touchdown went to tight end Drew Ogletree in the fourth quarter, who ran a slant from the right side of the formation to the left.

The Steelers were in a Cover 2 zone defense and appeared to have every other receiver properly guarded as they dropped six players into zone coverage. But, there was supposed to be a seventh player, and this time it was Bishop who forgot his assignment as he stuck to man coverage.

This error was more obvious, as it’s unlikely he was the only player who would be in man coverage while the rest of the defense would be in zone. That’s especially the case when you see the structure of the Steelers’ zone defense on the play, as the area Bishop vacated was the only space in the zone defense that was left open.

Those communication breakdowns hurt more when they waste opportunities where the Steelers had favorable alignment with their zone defense against the pass.

When in zone coverage, any defense is going to have spots where its linebackers can be exposed to covering the middle of the field against receivers. That’s an acceptable concession of a good zone defense, if the miscommunications aren’t happening where the Steelers are able to get the matchups they want — like they did on both the touchdowns allowed.

But natural mismatches will happen, and it’s the job of the defense to minimize their impact. During the fourth quarter, the Colts went empty set and put Downs in motion to move to the slot that lined him up against rookie linebacker Payton Wilson. Downs ran a slot-shake route, where his main role is to win inside leverage against Wilson to present an easy target for Flacco over the middle. Wilson needed to maintain inside leverage but fell for Downs’ false step to the outside to open up the middle of the field.

While that play resulted in a 13-yard completion, it wasn’t a backbreaker, and Wilson did a decent job of limiting yards after the catch. Again, that’s part of the design of the defense.

Turnover problems

Mismatches are a natural part of zone coverage schemes, but they are done so with the balance of giving your defense more opportunities to make plays on the ball. The Steelers’ scheme has created several opportunities for such plays through four games, and that’s led to their four interceptions — tied for fifth-most in the NFL.

But the Steelers are also tied for the most dropped interceptions in the NFL with four, and that tally was added to with missed opportunities in key situations Sunday. One play that won’t register as an official drop — but was certainly a missed interception — was the very first play of the game.

The Steelers dropped back into a Cover 3 zone on a play-action pass from Richardson and properly aligned Porter in deep coverage with his eyes to the middle part of the field to anticipate the pass on a deep ball to the middle of the field. This time, it was thrown to Michael Pittman on a deep post that cut underneath Minkah Fitzpatrick. Porter sees the route coming and lines it up, but just misplays the ball on his jump and allows a 25-yard reception.

On each of the Colts’ first three possessions — all of which resulted in points scored — the Steelers missed a turnover opportunity. Porter’s missed interception on the game’s opening play, DeShon Elliott’s forced fumble on Richardson on the second drive, and an actual dropped interception from Porter on the third drive all tallied up as missed opportunities for the defense to change the momentum.

That dropped interception was another play where the Steelers ran a Cover 3 zone and fooled the quarterback — this time Flacco — into throwing the ball right at Porter. But a simple drop from the second-year player from Penn State led to the missed turnover, and the Colts managed a field goal out of the drive.

As Tomlin noted in his Tuesday press conference, converting those opportunities is a “fundamental” part of the game that the Steelers work on pre-practice, during practice and after practice. But missing those opportunities takes away the primary positive for the Steelers’ reason to deploy zone defense as a regular part of their defensive scheme.

Conclusion

This brings us back to the fundamental question: were the Steelers’ issues on defense more about scheme and mismatches forced by the Colts, or self-inflicted mistakes in execution?

Looking at the tape, it’s more of the latter.

Take away the two communication breakdowns on the Colts’ touchdowns of 4 and 19 yards, add in at least Porter’s dropped interception, and the Colts would’ve finished with 139 passing yards over the middle — 220 gross passing yards — no touchdowns, and one interception.

That’s right along the pace of where the Steelers were in their previous three games when they averaged allowing 145 passing yards over the middle — 157.6 gross passing yards per game.

If anything, that tells you that the Steelers’ intended script had every opportunity to occur if they eliminated their missed assignments in zone coverage and caught a ball thrown right to them.

While some mismatches will occur at different points because of zone defense, the Steelers have to take advantage of the counter-balance that comes when mistakes are made by opposing quarterbacks. Otherwise, it renders a key component to why zone defense is played moot.

If Tomlin’s intuition is correct, the Steelers’ defense should correct its course and get back to playing at a high level for most of this season. Whether Tomlin is correct will hinge on whether his players can execute in these opportunities moving forward.

Should one game of missed opportunities turn into a trend, it will either force the Steelers’ defensive scheme to adjust or be the Achilles heel to the team’s 2024 campaign. But if the Steelers show that their defense is more about the pattern they established in their first three games, the Colts game will be just a bump in the road.

Look for that to be a focus this week against the Cowboys, whose 255.5 passing yards per game ranks fourth-best in the NFL.

By the way, the Cowboys rank sixth in the NFL in passing yards over the middle with 578 through four games, which is 57% of the team’s 1,022 passing yards.