Shanahan Scheme Analysis: Part 1

So what is it about Mike Shanahan’s wide zone based scheme that makes it so hard to defend? Every team runs wide zone runs (also called ‘outside zone’ runs), so what is so special about an offense based around this play? What is it that made Mike Shanahan tell SI, “if you really believe in the outside zone, if you can use those techniques in the running game successfully, you can adjust against all those defenses. It starts on a day-to-day basis, believing in what you’re doing.”

The fundamental principle underlying the wide zone scheme is to establish numerical advantages on offense. To flood one area of the field with offensive players, such that the numbers of defensive players in the area are outnumbered and overwhelmed. This may sound easy on paper, but remember that offense always starts out 1 (active) player shy of defense– where there will be 10 offensive players either running routes or blocking, they will be opposed by 11 defensive players covering/ rushing. A mobile quarterback changes that paradigm (since the quarterback must then be accounted for as an additional potential rusher), but with a traditional pocket-passing quarterback, there will be 10 players either running routes or blocking, versus 11 defensive players trying to stop them. How then to schematically create a numerical advantage?

The wide zone scheme accomplishes this by moving the entire offense in one direction– right at the snap, the entire offensive line/ TEs/ backs start running as one, sideways towards one of the sidelines. In the process, they are isolating one half of the defense to attack– since the defense doesn’t know which way the offense will be moving before the play, they must account for the whole field pre-snap. As such, large numbers of defenders are left completely out of the play, chasing after an offense that has lurched towards the opposite side of the field. Any defenders close enough to potentially pursue and tackle the runner are cut down by offensive lineman in their path, maintaining that play-side numerical advantage (when you start with a numbers edge, trading one for one (one blocker for one tackler) is always a sound strategy).

This numerical advantage also applies to the passing game. By forcing defenders to chase the movement of the offensive line/ backs towards one of the sidelines (remember, most under-center passing plays in the Shanahan system are blocked exactly like the wide zone run) the center of the field is vacated by most linebackers/ safeties. The route trees are then stacked to converge on that newly-vacated middle of the field, at various depths of field. Whichever defenders are left in this portion of the field then must make an impossible choice, between the many different receivers all converging towards the center, separated by 5-10 yards of vertical field space. All the quarterback has to do is drop the ball in to the least covered vertically aligned receiver. Again, the numbers end up favoring the offense.

So if this scheme is so good at creating numerical advantages on offense, then how did Vic Fangio manage to subvert this paradigm and overturn the numbers advantage? To such a degree that his blueprint became widely copied around the league (including by Bill Belichik in the Pats/ Rams Super Bowl, and then again by the Bengals (who despite their loss absolutely did shut down the Rams run game) in this year’s Super Bowl)?

The key to the wide zone run scheme is that the offensive line must be able to navigate cleanly towards one of the two sidelines, pushing defenders upfield along the way such that the running back is able to find creases in the defensive gap coverage. Because of the numbers advantage described above, offensive lineman are able to team block– two lineman together will engage a single upfield defender, pushing the defender backward and out of their assigned gap (after which the blocking o-lineman will generally turn further upfield and engage at the 2nd level). As a result, there are almost always going to be creases in the gap coverage of the defense, and if the defense over-pursues– tries to eliminate this offensive numbers advantage by jumping quickly towards the intended sideline– the running back cuts back towards the weakside, where lineman on the back side of the play have been cutting down pursuers (forcing those defenders to the ground, where they serve as further obstructions to any other pursuing backside defenders). In either direction (depending on which way the defense responds– static or over-pursuit) the offense wins the numbers game.

So the key to this offensive attack is that the o-linemen cleanly navigate towards one of the sidelines, with a numerical advantage in one of two directions. But what happens if a defender can make it into the backfield in the direction the offense is heading? This, traditionally was the way the wide zone scheme was defended– by lining up defenders extremely wide pre-snap (often in a wide 9 alignment– meaning that the DEs/ OLBs would line up even further outside than the TE), a defender would be in position to out-flank the o-linemen, and could jump into the backfield in the direction the running back was heading, preventing the offense from cleanly going wide and obstructing the path of the running back (forcing him to cut upfield before the blocking was established). The wide 9 alignment has indeed been used successfully for many years to defend the wide zone Shanahan scheme (and in fact, during SF’s 2019 Super Bowl season, their base package was a wide 9). However, while the wide 9 often successfully obstructs the path of the widest running lane, it doesn’t actually mitigate the numbers advantage that the offense enjoys by attacking one half of the field, so unless a defense sports excellent anchoring DEs/ OLBs and strong-tackling LBs (like SF did in 2019), the running game can still thrive by team-blocking one of the defenders out of their assigned gap. In other words, the wide 9 can successfully defend against this attack, but only with the correct high-level personnel. And fundamentally, the numbers advantage still lies with the offense.

Enter Vic Fangio in 2018. Up until the LA Rams faced Chicago in week 14 of the 2018 season, LA was enjoying an enormously successful offensive season. Todd Gurley was putting up prime Clinton Portis-type numbers (over 1800 scrimmage yards with 19 TDs in only 15 games), and Jared Goff was a legit MVP candidate, feasting off of easy throws over the middle of the field to the tune of almost 4700 yds (8.4 yds per attempt) with 32 TDs, 12 INTs and a 65% completion percentage. Sean McVay’s version of the wide zone scheme (run essentially as described above, except with 3 WRs and no FB in the base package) was absolutely tearing through the league. That is until Vic Fangio schemed up the perfect counter to the wide zone scheme– a way to remove the Shanahan-concocted numerical advantage of blockers vs defenders, and plug every available running gap, no matter which way the offense headed. Fangio didn’t go wide 9 (which is fundamentally a 4-3 alignment), or even 5-2 (as was often his base package in Denver). Fangio went 6-1– meaning he put 6 defenders at the line of scrimmage (with only one linebacker off the line), lining one defender against every single potential offensive blocker– all 5 offensive lineman plus the TE. By putting these defenders exactly opposite their offensive counterparts (or more accurately in the gaps between them), the defenders could mirror exactly what the offense did without first needing to head upfield. This meant that no matter which way the play headed, there was no numerical advantage for the offense– one defender for every blocker–which meant no team blocking, and no open gaps. The single set-back linebacker mirrored the motion of the RB, and if the play was a passing play, there were 4 defenders versus only 3 WRs (the TE and RB are covered 1 on 1 by the aforementioned members of 6-1).

Suddenly, the numbers favored the defense again. In Chicago, LA, which had been averaging over 33 pts per game, scored 6 against Vic Fangio’s 6-1 defense. Todd Gurley was held to 28 yards on 11 attempts, and Jared Goff went 20-44 for 180 yds, 4 INTS and zero TDs. Several weeks later in the Super Bowl, Bill Belichik copied this exact gameplan, grinding LA’s running game to a halt, and holding the Rams to a total of 3 points (tied with the 1972 Dolphins for fewest ever in a Super Bowl). Vic Fangio had schemed up the perfect counter to this otherwise enormously successful offense, and his innovation was copied league-wide during the 2019 season (which saw LAR fall from 32.9 pts per game to 24.6 pts per game, and from 13-3 with a Super Bowl berth to 9-7 and out of the playoffs entirely).

So how did Sean McVay, Kyle Shanahan, and (most importantly for Denver) Matt LaFleur respond to this defensive adaptation? Such that all three oversaw successful 2021 seasons/ playoff berths, with McVay ultimately avenging his 2018 Super Bowl humiliation?