No one is going to mistake the 2017 Indianapolis Colts’ offense for that of, say, the 2016 Atlanta Falcons or the 2007 New England Patriots. They’ve been less than stellar without franchise quarterback Andrew Luck and, while new quarterback Jacoby Brissett has certainly helped restore some order to what had been a chaotic mess of an offense, they aren’t going to find much success against the league’s better defenses.

The Pittsburgh Steelers boast one such defense.

Ranked second in the league versus the pass, allowing just over 180 yards per game through the air, the Steelers’ defense has thrived against nearly every quarterback they’ve faced outside of the Lions’ Matthew Stafford — who just happens to be the league’s highest-paid player, and it would be hard to argue he’s not deserving of it. Brissett is decidedly not on Stafford’s level, though he might be among the better quarterbacks the Steelers will face this year.

Brissett has a few major things going against him, though. First, his offensive line has consistently struggled to keep quarterbacks upright this season. That’s not a good thing, considering the Steelers are among the league’s leaders in sacks and quarterback pressure. Brissett can counter that to some degree with above-average mobility, but the Steelers have had a knack for getting several defenders into offensive backfields this season, meaning there is often simply nowhere for quarterbacks to run. And they’re often doing it with 4-man rushes, leaving seven defenders in coverage.

But the biggest issue Brissett is going to face is one that’s simply out of his control: the Colts run an offense that leverages concepts the Steelers’ defense should be intimately familiar with: short routes across the middle of the field (specifically, dig routes by outside receivers) and bootlegs on play-action.

As far as play-action passes on bootlegs, the Steelers see these at least twice per year, when they play the Baltimore Ravens, their arch-rivals. This has been more true than ever over the last two years, as the Ravens’ passing game has moved closer and closer to the line of scrimmage. In fact, the Ravens are near the top of the league in passes thrown to running backs, and they make heavy use of tight ends on short, outside routes as well.

But the concept the Steelers’ defense should be most familiar with are the short dig routes. That’s because they see them every week in practice. They are a staple in offensive coordinator Todd Haley’s scheme, and the Colts use them liberally, as well. Let’s have a look.

Short Dig (Drag/In)

Typically, when the primary route on a play is a dig (also known as a “drag” or “in” route), the idea is to draw the middle/inside linebackers away from the short middle of the field with other receivers. This can be accomplished in a number of ways: vertical seam routes, intermediate posts, etc. In the example above, the Colts get lucky: Houston is blitzing their middle linebacker. This could create problems, as a 6-man rush like this one can be difficult to stop long enough for the play to develop. But, because the short middle has been completely vacated, Brissett is able to throw the pass while receiver T.Y. Hilton is in the center of the field. Digs often need to develop further so that the receiver has completely cleared the linebackers or safeties playing the short middle, but the blitz here negates that.

The main goal of a wide receiver dig route is not to get three or four yards—it’s to put the ball in the hands of a fast, quick player in space. Typically, teams will run this concept with receivers who have one or both of those traits. Steelers receiver Antonio Brown is one of the best in the league (perhaps ever) at making plays in space when he has the ball, and Hilton is also quite good at it.

In the example here, the blitzing middle linebacker gave Hilton a nice assist. What really sprung the play, though, was the vertical route by the slot receiver. The Texans were in a Cover-1 shell with man-coverage underneath. The go-route run by the slot receiver carried the nearest defender way, way out of the play, giving Hilton room to run and time to size up the defenders.

Of course, this goes from a 40-yard pass to a touchdown thanks to Hilton’s exceptional move to avoid being touched by the defender as he went to the ground, then having the presence of mind to get up and keep running. But that’s what this sort of concept creates: get the ball into the hands of a playmaker in space and let him make plays. Hilton did exactly that.

PA Bootleg

The Ravens, as I’ve already said, make heavy use of bootlegs. Quarterback Joe Flacco has decent mobility and a good sense of when to run, so the PA bootleg is effective because it first draws the inside linebackers towards the line of scrimmage, and then draws them towards the bootlegging quarterback. Flacco is one of the best at waiting until the last possible moment to get rid of the ball in this type of situation, allowing him to drop the pass over the pursuing defenders. These plays usually result in three to eight yards (or more) after the catch, because they’re often paired with deeper routes on the outside to draw the cornerbacks and safeties away from the intended receiver.

Brissett is more mobile than Flacco, and so he presents an even greater challenge on bootlegs, because he’s more likely to actually pull the ball down and run. This means linebackers have to be extremely disciplined in their pursuit.

We saw the good and bad of this when the Steelers played the Ravens earlier this season. Early in the game, inside linebackers Ryan Shazier and Vince Williams were thoroughly fooled by a PA bootleg, to the point where they ran into one another. The result was a first down for the Ravens as Flacco found his tight end, who was all by himself.

Later in the game, though, Shazier recognized the bootleg and peeled back into coverage. He did it so well that Flacco never even saw him transition, and Shazier was able to undercut the route for an interception. This is the sort of read that inside linebackers have to be able to make on the fly to defend these plays.

In the example above, the Colts use a typical PA bootleg, but with the twist that tight end Jack Doyle comes across the formation behind the line of scrimmage, then leaks into the flat after the motioned receiver draws coverage away. But there’s another, more subtle reason why this works. Throughout the game, the Colts had been using Doyle on trap-blocks. With the play-action going to the offensive right, it was natural for Doyle to come across the backside of the formation to the left. The Steelers actually use a similar concept fairly often, mostly with tight end Jesse James or receiver JuJu Smith-Schuster.

The play-action works to perfection in this case, drawing both inside linebackers to the right and towards the line of scrimmage. This puts them in traffic once they read the fake, and they’re effectively sealed off from the play. The backside defensive end had read run due to the fake and was setting himself up to seal off a cutback. Doyle ran right by him, and there was no one there to provide coverage. The defensive end then peeled off to pursue Brissett on the bootleg, taking himself out of position to even assist with the tackle on Doyle.

These are the sorts of plays where Steelers’ rookie outside linebacker T.J. Watt has done a fine job reading the fake and dropping into coverage, as well, giving him a chance to get his hands up to knock down the pass or, perhaps, intercept it.

The Colts’ offense appears to be a favorable matchup for the Steelers’ defense: a young quarterback, a below-average offensive line and a scheme designed around concepts the Steelers see regularly. As long as they don’t make the mistake of taking an obviously inferior opponent too lightly, the Steelers’ defense should be able to effectively stop the Colts’ offense on Sunday.