I've spent a lot of time talking about
our offense, but it doesn't exist in a vacuum. The plays that are
called and the success that they have is largely dependant on what
the defense is doing, so if you really want to understand the Bear
Raid you need to understand the defenses that it faces. In this post
we'll look more in depth at quarters coverage (Cover-4), and the way
that we were able to break it on Trevor Davis' long TD reception against Northwestern. I
think that the commentors got this right on the TV broadcast so the
conclusion won't be a surprise, but this post will hopefully give a
deeper understanding about why Northwestern was running what they
were running, and will let you recognize this kind of thing for
yourself when it happens in the future. Also, if you see some of the
defensive stuff that I'm about to discuss happening in a game, you'll
know what kind of plays we should be calling!
The Nature of the Spread
First, let's look at what kind of passing game the spread can
accommodate that the I-formation can't. The mantra on TV broadcasts
has always been about “speed in space” and “winning 1-on-1's”
in the spread, but that really doesn't describe the spread passing
game. It's not about getting 1-on-1's and requiring guys to break
tackles (although that's where the explosive plays come from). At a
much more fundamental level, its about stretching defenses by
flooding zones with multiple receivers, making individual defenders
wrong no matter who they cover. This is why the spread started with
teams that had less talent than their competition (at least in its
most recent incarnation; TCU was already spreading the field to win
national championships in the 1930's:
https://www.youtube.com/watch?v=ZGqcGHX3xjQ). Over the last decade
spread concepts have become increasingly popular with more
traditional powers because the concepts are sound schematically, so
let's see exactly what kinds of challenges the spread poses for a
defense. Here's a basic spread formation:
We can compare this to a pro-I:
Both of these formations have a strong run tendency. I-formation
teams will usually run to the TE (right in the I-formation diagram), and will be
best at running to that side. They have more blockers over there,
and that lets them do more. Shotgun-spread teams, on the other hand, are usually going
to run in the direction away from where the back aligns (again, right
in the spread diagram). This is because, when in the shotgun, the
back already has to move to his right to get the ball from the QB.
Changing directions for a run to the left would slow him down and
make the play take longer to develop.
Against the I-formation, defenses can match this tendency by rotating
their coverage toward the TE:
Now they have two DB's to the right of the diagram and one safety in
the middle of the field, with only 1 DB to the left of the diagram.
The I-formation also has a clear passing strength, because one side
of the field has two receivers (the flanker (Z) and TE (Y)) while the
other only has the split end (X). When the defense rotates their
coverage toward the run strength, therefore, they're also rotating to
the passing strength, so they can match the offense's strength with their own.
This is more problematic against the spread:
Here once again, the defense is rotating toward the run strength (the
right side of the diagram). The problem is that, from the shotgun,
the left side of the diagram can very quickly become the passing
strength. The defense is rotating to the right side of the diagram,
but the offense has three receivers to the left. On the concept in the diagram above, this creates a
situation where X is able to run off the CB while the WLB is stuck in
between F and H, who are creating a horizontal stretch in the curl
and flat zones. It's not about making guys miss (at least to get the
completion), because the WLB can't effectively cover both guys at once. The shotgun specifically helps with this situation because the
back is aligned over the OT instead of behind the C and, on most pass
plays, is closer to the LOS, letting him get into the route more
quickly than a RB in the I-formation could. This is also why spread
teams like fast, pass-catching RB's. If the RB isn't a receiving threat here, the stretch becomes much less effective.
The other benefit of the spread against a secondary rotation is this:
The
spread (or really any 1-back formation) gives the offense the ability
to run four receivers straight down the field. A secondary rotation,
by definition, pulls one of the 4 DB's out of deep coverage and puts
them into underneath coverage, so the offense has a 4-on-3 matchup
deep, which is obviously a huge problem for the defense. In general,
this is the kind of thing spread offenses can do especially well:
because there are so many genuine receiving threats, with multiple
receivers on each side of the formation, they can create all kinds of
stretches on zone defenders and make it very, very difficult to cover
everyone without going to man coverage. Even when teams like tOSU and Oregon do pass, they're using these same kinds of concepts to spring guys open.
In short, the spread passing game and the nature of the basic spread
formation strongly discourage defenses from rotating their coverage
to one side of the field or the other. They need to play “balanced”
coverages, with two DB's on each side of the formation if they want
to match-up with all of the receiving threats on the field.
Quarters Coverage
For the reasons listed above, Quarters (Cover-4) is quickly becoming
a default way to defend spread teams:
First of all, how can you recognize quarters from the stands or on
TV? The obvious answer is that the DB's will be 4-across, but they
won't always be at the same level so it's possible to confuse
Cover-4 for Cover-2 or Cover-0. The best way to recognize Cover-4 is
to look at the depth of the safeties and their movement at the snap.
In Cover-2 the safeties will usually line up 12-15 yards deep, and at
the snap their first movements will probably be to get depth and
width, since they are the primary
deep defenders and so must be able to stay over the top of a deep
route by any receiver. In quarters, the safeties will line up 10-11
yards deep, and at the snap they'll stay still for a beat while they
make their read. The CB's aren't necessarily a reliable indicator of
the coverage, because within Cover-4, depending on the variant they
could do anything from playing press-man and following their guy
wherever he goes, to lining up 8 yards off the ball and bailing deep
no matter what. Also, the CB's on each side might be doing different things, so the CB's really don't tell you a lot. No matter what coverage you're looking
for, the safeties will always give you the information that you need
(that's why QB's read them). They're also perhaps the best indicator
of what's going on in the run game, if any blitzes are coming, etc.,
so they're really the best unit on the football field to understand
well.
The most obvious advantage to
Cover-4 is that you can easily defend 4-verticals. Your DB's line up
over the four WR's, and everything's easy as can be. Another benefit
is that in quarters, because the CB's are responsible for the outside
receivers deep, the safeties can play closer to the LOS; because
someone is already covering the outside receivers, the safeties' primary pass
responsibility is to make sure that the inside receivers don't run
straight past them, but other than that they can focus on defending
other things (especially runs and screens). A good quarters team can
get eight or even nine defenders involved against the run with good
safety play. This is why quarters is often used against Oregon-style
spread teams as well as Air Raid-style teams.
The big problem with quarters is that it is still vulnerable to
underneath stretches in the spread passing game:
Assuming that the FS and CB can't get involved underneath here (more
on this below), the WLB has the exact same problem that he had in the
rotated coverage discussed above. The big problem for quarters, and
for defending the spread in general, is in taking away these
underneath horizontal stretches. As the need to use quarters coverage has
expanded with the rise of the spread, defenses have also gotten more
sophisticated in their use of it, to the point that there are a
significant number of tags and variants that teams can use to take
away specific route combinations while still playing this nice,
balanced coverage.
First, let's look in more depth at a Cover-4 variant that can't
defend the passing play in the diagram above:
We can call this set of rules “Cover-4 Read.” On this variant
the rules are as follows: The CB is in man-coverage on the #1receiver (X) unless he goes inside. He can do this from a press alignment even better than he can from the off-alignment in the diagram above. The FS is reading the #2
receiver (H). If #2 pushes vertical, the FS covers him. If #2
doesn't, then the FS sits on the post and curl routes by #1 to help
the CB. This means that when #1 goes deep and #2 doesn't, the FS
becomes a deep defender, leaving the WLB stranded against F and H.
If a Cover-4 team is getting killed by the route concept in the
diagram above, they might switch to “Cover-4 Combo.” This
changes up the reads and rules for the DBs:
If
#1 (X) and #2 (H) both go vertical, then the CB and FS simply cover
them man-to-man, just as in Read. In Combo, however, the CB only
drops with #1 vertical until
he gets the flat threat. Meanwhile, when the FS sees that he isn't
getting any #2 receiver vertical, he immediately gets width and depth
to stay over the top of #1 (X). The CB takes F in the flat, the FS
takes X deep, and the WLB only has to worry about H. This really
becomes a more aggressive (from the safety's perspective) version of Cover-2. In Cover-2, as I
mentioned above, the FS would have been aligned at 12-15 yards at the
snap and would've gotten depth and width immediately, whereas in
quarters he aligns at 10-11 yards deep (making him a better run
defender) and only gets depth and width once he's made his read.
All of this gives you the knowledge that you need to break down
Trevor Davis' long TD pass:
Here are some things that are good to look for if you want to speed
up your own recognition while you watch games live, and to help to do
your own immediate breakdown once a play's over: How deep is each
safety at the snap, and where are they? Why does Northwestern have
to use a coverage variant that puts the CB in the flat at the bottom of the screen? Using what we now know about quarters, why do the DB's at the
top of the screen do what they do? Are there any other structural
deficiencies in the way that Northwestern's defended this play?
Bonus points to the first person to name the pass concept we're using
here. Let me know what you see: http://bearinsider.com/forums/showthread.php?85803-Bear-Raid-Breakdown-TD-s-TD
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