Trap Coverages – A Quarters Check

As we discussed in the last post, one of the weaknesses of Quarters is the flats against a strong run game and especially out of 10 personnel.  Because they are run first players, the SAM and WILL have to respect the run game, making it difficult to cover the flats if #2 to their side is immediately out on some sort of bubble or quick out.  This is especially true of the weak side away from the back, as the OLB must respect the zone run to his side and thus cannot expand in time to cover his flat.  

When that happens, Quarters defenses answer with a trap coverage, designed to free up the CB to play the out-breaking route from #2 while passing verticals from #1 off to the S on that side.  This is a Quarters check that operates as the defensive equivalent of a constraint play.  Early in the season, we saw a couple of different trap looks from the Blackshirts.

Play 1 – 2 Trap With 5-Man Pressure

Personnel: 10 (1 RB, 4 WR)

Formation: 2 x 2 (Double Slot)

2 Trap 5 Man Pressure

This is a 5-man pressure bringing the SAM from the boundary while the DE and DT to his side long stick away from him.  Behind it, and because of the split of #1, the Blackshirts play man-to-man coverage to the field side to free up the WILL to play run.  On the boundary side, the Blackshirts are matching 3 over 2 in what is known as 2 Trap/Read or Palms.  Both the SS and CB are reading the #2 receiver’s release.  If he releases vertical, it becomes Cover 2: the MIKE in this case zones off and looks to “trap” any hook by #2, the SS plays #2 vertical in his half, and the CB collisions #1 and sinks to the hole to protect against a corner route from #2.  If the #2 receiver releases inside, it also plays as Cover 2: the SS alerts “in in in” and #2 now becomes the concern of the WILL and MIKE while the SS looks to #1 and tries to rob any inside breaking routes from #1.  So far, so good, and not that difficult for the QB to read.

What changes is what happens when #2 goes out.  With the SS and CB both reading #2, if he breaks immediately out, the CB will jump the route and “trap” or “rob” it while passing off any vertical by #1 to the SS.  This isn’t a new coverage for Nebraska fans, as it was a Bo Pelini staple (“Palms” here) and Zac Taylor threw a Pick 6 against OU in 2005 against it too.  

Defenses also have to account for the RB, or #3, out of the backfield on this play.  One way to accomplish that is to put your edge blitzer in a “peel” technique.  If the RB immediately runs to the flat, the blitzer “peels” off and locks up the back man-to-man.  Other defenses spy with one of the DL (usually an interior NT or DT) or simply allow the RB to release to the flat without peeling.  If they cut the RB loose to the flat, the ball has to come out fast and the defense asks the second- and third-level defenders on that side of the ball to rally to it.

The benefit of 2 Trap is that it answers the bubble and go problem that teams often try to present to Quarters defenses.  In Quarters, where the weakness is the flats, the OLB and S are outleveraged against the bubble.  The CB has to fight hard over the block of #1 to consistently stop the play.  After a few times of doing this, teams will dial up the bubble and go to take advantage of the CB’s overaggressiveness trying to jump the bubble.  To free up the CB without risking a bust on a bubble and go, teams will run 2 Trap because the corner can jump the bubble from #2 while passing off #1 vertical to the safety.  That’s exactly how Nebraska handles this inside zone play tagged with double bubbles:

2 Trap Double Bubble.gif 

To the boundary, you can see both Davie and Gerry reading #2.  As soon as #2 is out on the bubble screen, Davie triggers down and Gerry works down to #1, who is blocking on the play.  On the field side, with Cockrell in man coverage, he immediately triggers on the bubble while Kalu takes the vertical of #1.  This gets the 5-man pressure and also lets Weber (MIKE) and Young (WILL) get involved in the run game to stop this inside zone for a one-yard gain.

Play 2 – 2 Trap With 4-Man Pressure  

Personnel: 10 (1 RB, 4 WRs)

Formation: 2 x 2 (Double Slot)

The very next drive, South Alabama came out in the double slot formation one more time, this version with the RB to the field.  Again, common formation for the bubble screen because the OLB to the field side, in this case the WILL, has to protect against backside cutback on any inside zone.  In doing so, it’s almost impossible to get back out to the bubble in time.  Thus, Banker again dials up 2 Trap with a standard 4-man pressure from the defensive line:

2 Trap.jpg

South Alabama calls a bench concept to the boundary side, thinking that Nebraska will be in base Quarters against the double slot formation.  If Nebraska was in base Quarters, this would be a stressful route combination.  Because #1 is vertical, the CB would lock him up man to man.  With #2 out under 5 yards, the FS would look to #1 and leave SAM to expand to the flat on #2.  As you can see from the film, that’s a tough ask of the SAM, Marcus Newby, because he’s apexed between #2 and the LT. From this alignment, #2 outleverages him to the sideline.

In this case, however, with 2 Trap called, Nebraska has the right coverage called for this route combination, though the execution breaks down a bit.  With #2 out immediately out, Kalu, the CB, passes off #1’s vertical to the FS and traps #2’s out route.  Newby is playing “slice” technique, meaning he’s taking a curl drop and then widening out to the flat if #2 is immediately out.  Reading #2, once he’s out, Cockrell will now play the vertical route by #1 as the CB passes him off to Cockrell’s deep half.

2 Trap Base.gif

Kalu and Newby are in great position to defend #2 inside/out if the QB throws the quick out.  Instead, the QB chooses to hit the hole shot to #1 vertical and Cockrell is a beat slow in getting over there.  As Banker is fond of saying, the other guys are on scholarship too.  Nice read by the QB to avoid the trap coverage (though you see him pat the ball a bit when the trap comes), and a nice job by the #1 WR settling in the hole rather than running into Cockrell’s coverage.

Wrapping It Up

2 Trap is a nice way to keep the offense guessing.  Pre-snap it looks identical to Quarters, and with the CB trapping out routes, it frequently delivers big hits on the perimeter against unsuspecting WRs.  And when paired with pressure packages, just as Zac Taylor found out against OU, it’s a way to get interceptions with a lot of open field in front of the DB.  Look for Banker to continue mixing 2 Trap/Read in with our base Quarters and expect it to generate at least an INT or two next year with the Blackshirt DBs now more comfortable passing off routes within the concept.

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