Column: Matt Eberflus’ defense was the NFL’s toughest on 3rd down last year, one scout says. How will the Chicago Bears reflect that?

In a casual conversation with a scout a few weeks back, he said the most difficult defense to prepare for last season was the Vic Fangio-led Denver Broncos — no surprise considering the complexities the former Chicago Bears defensive coordinator is known for.

In the next breath, the scout said the defense that was most problematic on third down was the Indianapolis Colts under Matt Eberflus.

The Colts?

Eberflus had some fine players to work with, including tackle DeForest Buckner, linebacker Shaquille Leonard and nickel cornerback Kenny Moore, but the Colts probably weren’t on anyone’s short list of the most imposing defenses in 2021.

So what made them so challenging on third down — the money down — and could that be a sign of things to come for the Bears as they prepare for Sunday’s season opener against the San Francisco 49ers at Soldier Field?

The answer takes you into the weeds a little in terms of defenses and coverages and disguises and more. Suffice to say that Eberflus — who learned the NFL game from Lovie Smith and champions the Tampa-2 scheme that was such a big part of the Bears’ success under Smith — has a lot more tricks in the bag, especially when the defense has a chance to get off the field on third down.

Eberflus has given play-calling responsibilities to defensive coordinator Alan Williams, but they worked together in Indianapolis so it’s fair to assume Williams will have much the same in mind.

While the Colts leaned heavily on split-safety looks on first and second down last season, on third down they were in man free coverage 46.9% of the time, the fourth-highest figure in the league. That’s a zone-based team turning to man coverage. They also blitzed 34.7% of the time on third down, the eighth-highest figure in the league.

“For me, last year was my first year in the system, it was a little surprise for me,” Bears cornerbacks coach James Rowe said when I asked him about the depth of the options the Colts had on third down in 2021. “But they say when you go back and really look at those teams from the past, (Cover-2) wasn’t always the call. They just probably did it more than everybody else.”

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Said middle linebacker Nicholas Morrow: “You’ve got to throw different looks at offenses. Even if you run the same coverage, maybe use different personnel or have different people doing different responsibilities in that coverage. Do that and on offense, they don’t know who is playing what role.

“To affect the quarterback, you can do it with pressure and you can also do it with your pre-snap alignment and personnel. I think that helps you and takes away from you having to use a five- or six-man pressure when you affect the quarterback with so many different coverages.”

What Eberflus and Williams decide to do with new personnel remains to be seen and could be matchup-dependent from week to week. But if they draw on their combined experience in Indianapolis, the Bears will rely heavily on split safeties on first and second down and then be more aggressive going after the quarterback on third down.

What would follow — again, if the Bears piggyback off what the Colts did in 2021 — is a mixture of zone and man pressure with a lot of late rotation by defensive backs and even linebackers.

Every defense in the league uses some version of Cover-2, and it never will go out of style because it puts the defense in position to take away the deep ball while forcing quarterbacks to be patient and work underneath throwing windows.

Smith bet on his defense in that scheme, counting on offenses having difficulty driving the length of the field by taking the short stuff without making errors. The Bears had star talent at the key positions, too, starting with Tommie Harris at defensive tackle, Brian Urlacher at middle linebacker, Lance Briggs at weak-side linebacker and Mike Brown at free safety. They added top edge rushers such as Adewale Ogunleye and later Julius Peppers.

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Defenses turned to Cover-2 variations to slow Patrick Mahomes last year, and he was flustered for a while before coach Andy Reid and the Kansas City Chiefs adjusted, turning to more of a quick game that looked for catch-and-run opportunities as explosive shots downfield were limited.

It will be fascinating to see how the Bears defense takes root — how veterans Robert Quinn, Roquan Smith and Eddie Jackson settle in and how rookies Jaquan Brisker and Kyler Gordon fare. Much of the focus will be on quarterback Justin Fields as the Bears try to establish an identity on offense, but there’s much to be learned about a defense that goes far beyond a static Cover-2 shell.

“It’s not just different coverages but how you can make man look like zone or zone look like man, different disguises,” cornerback Jaylon Johnson said. “It’s just how you want to match up.”

The first clues arrive Sunday. With any luck, maybe opponents will consider the Bears a handful on third down in the near future.