Curls Part 2 of 4: Four Across

Now that we have a base read for a single high safety, we go to the other extreme with two high safeties plus backed off corners.  This look, with four defenders relatively high, is what you see with either Cover 4 or Quarters coverage.  

Either way, whether this is man or zone, the defense has backed off a lot of personnel and has very little up front in run support and for underneath coverage; they are trying to stop the pass.  If we are running the ball, this is great.  But what if we have Curls called against this?

Vertical stems

The defense is committing many players deep to prevent long gains, but still has at most 8 players to drop into coverage (if there is just a three man rush).  Under normal circumstances with a four man rush, there will only be three defenders to play the short passes.  Consider Cover 4 from the Nickel Normal formation:

This is a defense that eliminates the possibility of anything past 15 yards like a verticals play and can play the run because zone defenders do not have to worry about getting depth at the snap.  But when the play is a pass and the offense attacks underneath, this is a weak call.  Not only are there only three zones being covered, but two of them in most personnel packages will be linebackers.

The feature of the Curls play that helps us to attack underneath is the presence of many routes that all go straight upfield like a verticals play.  Although the receivers do not end up going vertical all the way, defenders assigned to them must honor the possibility their man will turn on the jets and try to get behind the defense.  This is the same vertical stems idea talked about here at Her Loyal Sons:

All of the receivers push vertically at the snap. Prosise’s seam route holds the safety and forces the corner covering Jones to stay over-the-top. Jones presumably has the option to break off his route based on the corner’s depth. He ultimately pushes to a depth of about 10-12 yards and turns for the ball. Rees throws the ball to Jones’ outside shoulder to minimize the threat of the linebacker undercutting the throw. The result is an easy first down. 

This play illustrates how the Irish use vertical stems against Cover 4 to open up the short outside zones. The inside vertical route prevents safety help on the outside and forces the corner to play more conservatively. Rees completed similar passes to Jones, Daniels and Chris Brown for easy 6-12 yard gains all game long.

In our play, we have the same vertical push by the wideouts split far to the right and left as well as the slot receiver.  The only receiver not running vertically at the snap is the tight end:

The slot receiver's post route has the same effect as the inside vertical - it holds the safety and forces the outside coverage to stay over the top.  Strongside, this means the safety in a four high look is sitting over the post and the outside corner must stay deep against what becomes a curl.  But look at what Fishduck says about the coverage:

Now, this isn’t man coverage, though it can quickly become very similar. Different teams run the coverage in different ways, but the main point to understand is that the corners and safeties are responsible for the guy they are aligned over if that receiver goes vertically up the field past 8-10 yards. If that happens, then they are in man coverage.

Go back to what  we're looking at in the first picture from the top.  There are corners aligned over each wideout and the defense has a guy over the slot man.  The slot post route will run right through his assigned zone, so he must stay with the slot man and carry him to the deep safety.  The vertical stem gives the man assigned underneath coverage on the strongside a terrible choice: defend the stem and take away the 8-12 yard gain or abandon it and run to the flat where the TE is leaking out to take away a possible 5-10 yard gain.  He stays home to take the hook/curl away "and must never let someone go up the seam undefended."

That means there is nobody on the TE arrow.

Attacking the flat

When you see the four high look with the cornerbacks backed off the line of scrimmage further than whoever is covering the slot receiver, the read we make is to hit the TE for a decent gain.  Remember, the defense is set up to take away your deeper throws, so this is taking the free yards being offered.  This makes Curls a great first and second down call.  The main thing is: don't stand there and pat the ball hoping someone gets open against the blanket coverage downfield.  Make the read and get rid of it:

This is a safe read with an extremely easy throw to make.  You can count on this read avoiding negative or zero yards, but it will not pick up medium to long yardage.  If you see this on third and 8, you'll have to either gamble that you can make the throw in front of the cornerback - or better yet check to something else.

The timing on this throw is a 3 step drop - the QB takes the snap, and drops one step then gathers with two short steps and fires.  Instead of letting the QB go into his entire 5 step drop, we snap the ball and almost immediately fire the ball to the TE.



The relative success can be affected by the read/ability of the inside linebacker (if he gets over to the TE fast) and how well your wide receiver can pick up the block downfield on his corner.



Even if the coverage is not Cover 4, you can often pick up decent yardage from the alignment advantage alone.  In Madden, this is even more effective because the downfield blocking logic is better than it is in NCAA.