Under the Microscope: Examining the parallels between the O-line and secondary

From a purely physical perspective, offensive linemen and defensive backs couldn’t be any more different. On average, tackles are 6’5” and 315 pounds and are generally viewed as members of the least athletic position group on the field. The typical cornerback is six inches shorter and more than 100 pounds lighter than the standard tackle, and they’re oftentimes the most athletic players on the field. But when you examine each position from a technique and strategic standpoint, there are many more parallels than you might initially suspect. This piece looks to uncover some of those similarities using film, anecdotes from former and current pro players and coaches, and other observations based on my time studying the game.

First, a few overarching similarities between the two positions that we will break in more detail:

1. Moving backwards at the snap on passing plays while having to mirror the opponent and maintain a specific amount of spacing, leverage, and timing with your line mate or fellow defensive back.

2. The footwork and hand technique is similar, with corners in press man coverage and O-linemen on an island in pass-protection, specifically with linemen jump-setting.

3. Corners passing off ‘switch’ or ‘rub’ routes compared to linemen passing off stunts and twists in pass-protection.

4. Centers and free safeties are often the ‘quarterback’ of their respective units, with an extensive checklist in the pre-snap phase of the game and more of a mental load than every other position on the field except the quarterback.

5. Zone and man-match coverage for the secondary is comparable to slide protection for linemen, in terms of responsibility for certain areas until the opponent declares, with an advanced sense of leverage, spacing, and knowing the location of your help.

6. There are either four (DBs) or five (OL & DBs if the defense is in nickel personnel) on the field at the same time, which is more than any other position. This requires an unmatched level of teamwork and reliance on the man next to you for success. This also leaves both groups uniquely vulnerable when there is a weak link, so it’s often best to be solid across the board with quality depth to maintain competency and counter the battle of attrition that comes with an NFL season. 

7. Another similarity is how obscure the analysis seems to be for each position from the outside looking in, partly because of the ‘team within the team’ dynamic that each group has, making it very difficult for outsiders to assess responsibilities on a given play due to the interdependence of players within the unit.

8. Access to the sideline copy and end-zone copy are prerequisites to study and evaluate each position properly, as opposed to just watching the TV copy of the game.

9. Playing 58/60 perfect snaps in a game but giving up a big gain or touchdown and a key pressure or sack on the other two reps would be considered a poor game for each position group.

Let’s look at a quick scenario to illustrate some of the similarities in more detail. It’s 3rd and 9 from the offense’s own 30-yard line late in the 4th quarter, with the team in possession down by six points. It’s likely their last chance to prolong a drive to retake the lead, and everyone on the field expects a passing play. The play-caller wants to ensure he gets four receivers into the route so the O-line’s best player (in this case the left tackle) is left on an island against the opposing edge-rusher. The defense looks to be bringing an overload pressure from the opposite side, so the line is sliding away from the left tackle, putting him on an island (a similar dynamic to Cover-3 mable with the backside corner in man coverage while the opposite side plays zone). The quarterback is set to take a five-step drop. The tackle is going through his pre-snap checklist and is taking all of these details into consideration while knowing that (a) he needs to move at a backwards angle to get to his spot before the rusher (think press-man coverage for a corner), (b) the initial 2-3 yards after the snap are the most important part of the rep, (c) he can’t get beat inside since that is the shortest path to the QB (corners have a similar awareness of leverage on their man), and (d) he needs efficient footwork out of his stance to establish the proper positioning and leverage on the rusher to intersect him and keep the QB clean. As 9-year NFL veteran cornerback Darius Butler told me about technique in man coverage from a corner’s perspective, “Man-to-man coverage is most important in the first 2-3 yards. [The] QB may work off you if you win that initial battle.”

In the scenario above the defense is in Cover-3 Mable, with their best corner isolated against the offense’s ‘X’ receiver on the backside (similar to the line sliding away from the left tackle, neither the CB or OT have immediate help). The corner is playing press man with outside leverage on the receiver, so he needs to funnel him inside and not get beat outside since there is no guaranteed safety help over the top (the tackle knows there is likely no guard coming over to secure the inside gap, so he can’t get beat inside). The corner knows that the initial 2-3 yards of his engagement with the receiver are the most important, so having efficient footwork out of his stance without any false steps will ensure that he can establish proper positioning and leverage on the receiver to disrupt his timing in his route (very similar dynamic with the tackle’s approach).

This isn’t an exact replication of the above scenario in terms of down and distance (this is 2nd and 10 from the 45-yard line), but you can see how the backside corner is in a similar situation to the left tackle (both in ‘man-on-man’ situations) that requires familiar initial technique near the line of scrimmage.

Another example of how a corner in press-man coverage uses similar initial technique as a tackle in pass-protection is shown below with Patriots CB Stephon Gilmore and Packers LT David Bakhtiari. After the initial few yards the comparison starts to break down because of how much more space the corner has to deal with, but focus on how they establish leverage on the opponent, handle their footwork, and create initial angles.

When corners decide to be more physical and jam a receiver at the line of scrimmage in press coverage rather than just establish position and mirror, the hand technique and mentality is very similar to when an offensive linemen executes a jump set.

Former Bengals All-Pro RT Willie Anderson told me that he sees a tremendous amount of carryover between the secondary and O-line play, particularly in the passing game. Anderson explained why with a story from 1994, when he was playing at Auburn and asked Tigers quarterback Dameyune Craig to explain what made Deion Sanders so great. Craig — now the WRs coach for Texas A&M — told him that it Sanders’s ability to stay square longer with the WR relative to other CBs because of how confident Sanders was in his speed. When most DBs would turn their shoulders and give receivers two-way gos, Deion would still be square with the leverage advantage. When Anderson got to the Bengals in 1996 then-OL coach Paul Alexander asked everyone who their favorite player was. “I said Deion Sanders, and coach got mad because it wasn’t a fellow O-lineman. But I explained that it was because of Deion’s technique, specifically his ability to stay square longer with the receiver than other guys and not turn his shoulders too early, which prevented a two-way go.”

Staying square in man coverage or in pass-protection longer than the receiver or rusher is almost equally important for the success of each position. Anderson went on to say that “the tackle becomes like a DB versus the rusher in pass pro. Rushers are the receivers. They give you ghost routes and ghost moves to give something and take it away.” Staying square and not biting on these ‘ghost’ moves is critical for success on both sides of the ball.

Here are a few examples from Chargers WR Keenan Allen, All-Pro edge-rusher Melvin Ingram, and Panthers DE Brian Burns showcasing what it looks like to set up a route or move by starting their movement in one direction before snapping off in the opposite direction.