Josh McDaniels and the Slant-Flat Concept in Super Bowl XLIX

Josh McDaniels chose the slant-flat route combination as the principal concept for his game plan against the Seahawks defense during Super Bowl XLIX. It combines two quick underneath throws in a high – low read progression that was popularized by Bill Walsh in the 1970s and 1980s. Historically, defenses in that era predominantly ran Cover 3 and Cover 1 shells which meant that they were susceptible to the short passing game. Due to the simplicity and effectiveness of the slant-flat play, Bill Walsh was able to build an empire based on this concept and it was this concept that popularized the Cover 2 defense in the NFL in order to stop this concept.

The Slant-Flat Play Explained

The first progression is the slant, while the second progression is the flat. After the snap, the quarterback reads the outside linebacker or the slot defensive back that has the flat responsibility. If that flat defender vacates to cover the low flat throw, the QB throws to the slant wide receiver. If the flat defender sits in the high slant passing lane, then the QB throws to the uncovered low flat wide receiver.

It’s the slant receiver’s job to win inside and underneath the bailing cornerback. If the defense is in Cover 1 Man-Free Safety (as indicated by a defender following a receiver in motion), then the only pre-snap adjustment is for the slant receiver to create a rub/pick to get the flat receiver open. The slant-flat is, in theory, one of the best passing concepts to use against Cover 3 as the concept doesn’t try to force anything deep against a defense built around containing the long passing game.

The slant-flat’s simplicity and ease of execution, with only one key defender to read, makes it a popular concept for high-school-level quarterbacks, and it’s still an effective play call for pocket passers across the NFL. The Seahawks, with their Cover 3 and Cover 1 defensive shells, were not immune to its effectiveness as seen in the NFC Divisional round by the Carolina Panthers as well:

Play 1
Description: Carolina Panthers execute slant-flat against Seahawks Cover 3 defense. Touchdown.

Variations of the Slant-Flat Play

Combining a draw play-fake to hold aggressive LBs in the box at the beginning of the play was one of the many clever details McDaniels used to hinder the pass rush while providing receivers with more space after the catch. Yards after the catch (YAC) is highly stressed in McDaniels’ offense, which is the reason why hard-nosed players such as Wes Welker, Julian Edelman, and Danny Amendola are brought to Boston.  Here Brady throws to the flat route or second progression of the high/low OLB read.

Play 2
Description: New England Patriots complete 3 yd flat route against Seahawks Cover 3 defense. 10 yd gain for 1st down.

Here Brady throws to the slant wide receiver for the touchdown as the flat defender covers the flat route.

Play 3
Description: New England Patriots complete 11 yd slant route against Seahawks Cover 3 defense. Touchdown.

In this play, notice how the play-side tackle grabs and yanks down the DE’s jersey, keeping him from potentially jumping up for a pass tip on the low trajectory. That’s by design and not by accident. Other times the play-side tackle actually catches the DE by surprise with a cut-block, for the same effect on this play.

Play 4
Description: New England Patriots complete 1 yd flat route against Seahawks Cover 1 defense. 7 yd gain.

Little details like this are found all over the place in McDaniels’ offense. Most other teams don’t achieve this level of detail, and teamwork, where offensive lineman are not only blocking to protect the QB, but are also taught to be aware of the routes, the timing, and the passing lanes they need to open up to execute the play. The Patriots truly represent teamwork at its finest.


This time the DT is ready for the play, getting good penetration by the bull-rush into the passing lane before elevating for the pass deflection. If not for him, the Patriots would have had another good gain to TE Rob Gronkowski on the slant route.

Play 5
Description: New England Patriots slant pass blocked in backfield against Seahawks Cover 1 defense. Incompletion.

Just to keep the defense guessing, the slant/flat concept has a sister play which exploits the same weakness of the Cover 3. This play is known as the curl/flat or slot-hitch/flat combination seen here.

Play 6
Description: New England Patriots complete 5 yd curl route against Seahawks Cover 3 defense. 6 yd gain.

Different formation/routes, but with the same read, same progression, and same passing lanes as the slant/flat makes the play effective.

Another good cut block on the play-side DE. This time SS Kam Chancellor is assigned to stop the slant-flat. Watch how he expertly sits in the slant area then explodes towards the flat wide receiver to ensure that the receiver doesn’t get any YAC.

Play 7
Description: New England Patriots complete 2 yd flat route against Seahawks Cover 3 defense. 3 yd gain.

Here we see the defense in Cover 1 Man-Free try to stop this concept. In this play, we see the outside receiver shorten his route to create a rub traffic jam upon seeing the manned defender follow the slot receiver motion. This rub route gets the flat receiver open. On the opposite side of the ball, a RB screen is executed, with both receivers setting up blocks. Against Cover 1, the RB is manned by the LB. It’s three defenders on three receivers at the top of the image, and two defenders on two receivers at the bottom. Brady knows pre-snap to go to the two receiver side with the rub slant-flat.

Play 8
Description: New England Patriots complete 2 yd flat route against Seahawks Cover 1 defense. 8 yd gain.

In the Super Bowl, McDaniels calls the same exact play back-to-back to push Seattle into making a defensive adjustment. There is a special joy shared by play callers when a game plan is working well enough to do this. The RB screen opposite to the slant-flat that is not very effective against Cover 1, nor a standard Cover 3, but McDaniels game planned that it would be useful should the Seahawks shift an extra defender to the slant-flat side, while in a Cover 3. Here, the Seahawks makes the adjustment McDaniel’s was expecting the Seahawks to make. They use a Cover 3 variation with SS Kam Chancellor shifting over outside the hash, deep in the second level to help on the high slant. In a standard Cover 3, there are four underneath defenders playing inside-out flow.

But this play, SS Kam Chancellor shadows Julian Edelman in motion to provide an extra body to help on the slant. He lurks in a SS Cover 3 “Buzz” position over the slant passing lane, leaving just 3 underneath defenders. The middle/hook defender now has more middle responsibility, allowing RB Shane Vereen to catch a flare with space to run after the catch.

It’s a numbers game: three defenders covering two receivers on one side of the hash, leaving just 2 defenders covering 3 receivers (including RB Shane Vereen) on the other side of the hash. Brady identifies (pre-snap) the lopsided coverage adjustment, and executes the game plan for this coverage adjustment — a quick fake look to the slant-flat side to hold the middle linebacker over the center, then throwing it back to the RB screen to the opposite side. The RT’s cut block misses the DE, so Brady is forced to lob the throw. Otherwise, the play had potential for more. Even without the big gain, the threat would keep the Seahawks from attempting this Cover 3 “Buzz” variation to stop the slant-flat again.

Play 9
Description: New England Patriots complete flare route behind line of scrimmage against Seahawks Cover 3 buzz defense. 5 yd gain for first down.

The sheer effectiveness of this play dismantled the Seahawks Cover 3 and Cover 1 defense, so much that they actually abandoned those coverages and ran Cover 2 and Cover 6 by the second half. This begs the question: Why was it so effective and why does it seem like it’s never been done before? Further, why did the Broncos’ offense use other passing concepts that were blatantly ineffective in last year’s disappointing Super Bowl when this simple slant-flat play concept was designed specifically for the Cover 3 and Cover 1 defense that the Seahawks run?

Part of that answer has to do with tendency of the NFL to want to go deep and attack the downfield game as opposed to sticking with dink-and-dunk play concepts. Star wide receivers don’t get mega contracts when they only catch two yard passes with three yards after the catch even though it’s a critical element to the game of football, while fans get upset about the lack of a downfield threat due to the “appeal” of game-changing plays. This pressure causes coaches to risk bigger plays.

The other part of the answer has to do with the Patriots mentality of teamwork and game planning. This play along with other underneath passing plays formed the bread-and-butter to their entire offensive game plan. The Patriots sparingly mixed in deep passes only when they knew they had the matchup for it. Most teams and play-callers rarely have that kind of discipline to stick with the strategy and end up adjusting away from it too quickly. But unlike many teams in the NFL, the focus of the 4x Super Bowl winning Patriots offense is not on star players. It’s the intangible play calling, game planning, and teamwork that is apparent in the way the Patriots play the game of football.

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Jeff Kim

Jeff started playing the game as an ankle biter in peewee football. It was there that he began taking his dad's game recordings shot on VHS camcorder, breaking it down and offering play fixes and adjustments to his youth football coaches' chagrin. He has fond childhood memories of cheering on the Redskins with his dad during their glory days, but has been a fan of coaches rather than teams throughout his life. After high school football, he began taking collegiate and adult flag football way too seriously, teaching and coaching the West Coast Offense to backyard quarterbacks, and collecting championships along the way. Jeff enjoys keeping his ear to the ground as the cat and mouse game between offenses and defenses gyrates forward.