|Big thanks to friend of the blog Andrew McIntyre for the play diagram. I'm working on getting a copy of Adobe Illustrator so I can make slick diagrams like this.|
Michigan comes out in a 3-4 set: Craig Roh is the SDE, Will Heininger is playing DT, and Nathan Brink is the WDE. All of the linebackers (Kenny Demens, Brennen Beyer, Brandon Herron, and Jordan Kovacs) are on the line of scrimmage showing blitz. Demens and Beyer are on the strong side of the field (bottom of the screen) while Herron and Kovacs are on the weakside (top of the screen).
WMU is in a 4-wide set, and it's unlikely that Michigan is bringing all of the blitzers on the line of scrimmage. Michigan's corners and safeties are playing 7-12 yards off the line of scrimmage. Fortunately, because Mattison pressed all of the linebackers onto the line of scrimmage, Carder is unable to get a read of who is and isn't blitzing.
Right as the ball is snapped, Demens and Beyer drop into coverage. All of the defensive linemen show blitz (though not all will blitz, about which more in a minute), as do Kovacs and Herron on the weakside of the play.
At this point, DT Heininger pulls up from his blitz and drops into zone coverage. Now we can really see what Michigan is running: quarter coverage from the corners and safeties with Beyer, Demens, and Heininger playing zone coverage underneath. And while there's a weakside blitz, Michigan is able to drop seven men into coverage here and still get pressure.
More immediately, you can see Kovacs stunting (red) behind Demens on the weakside of the play. The principles here are the same as what we saw yesterday only with different personnel. Brink was lined up outside of the right guard at the 3-tech position; Herron was outside of the right tackle in the 5-tech position; and despite the absence of a TE or H-back, Kovacs was lined up in the 7-tech position. With Heininger bluffing a blitz from the DT spot, that leaves on the right guard and right tackle to block three Michigan rushers.
The right tackle has taken the bait: Herron rushed directly upfield to open up a hole in the weakside B-gap. The guard, having not recognized Kovacs in the 7-tech position, immediately blocks Brink on the inside. After seeing Heininger drop into coverage, the center joins the right guard and doubles Brink leaving Kovacs completely unblocked.
At this point, it's all about Kovacs executing the sack. But more importantly, look at the coverage. On both sides of the field, Michigan has coverage over the top from the safeties and corners in quarters, while Heininger and Beyer are taking away the underneath throws to the receivers. The WMU running back is sneaking out of the backfield as a release option. Demens, who is currently covering the underneath middle of the field will be responsible if the RB ever becomes a viable receiving option...
...but you know what happens next
You can see Herron screaming around the backside of the play after beating the right tackle upfield. He'll eventually pick up Alex Carder's fumble and rumble into the endzone for the second defensive TD of the day.
Once again, the replay gods have blessed us with a great view of this play. Below, you can see the linebackers crowding the line of scrimmage and the alignment of Brink, Herron, and Kovacs. Also note Heininger lined up directly over the center.
As the ball is snapped, Heininger, Demens, and Beyer drop into coverage while the weakside linebackers/Brink attack the line of scrimmage.
As Herron rushes upfield and Brink engages the guard and center, Kovacs has a clear shot at Carder.
It's been noted that Western Michigan was breaking in a handful of new offensive linemen, but these blitzes are largely independent of the opposition. The idea here is to overload one side of the offense and force opposing quarterbacks to make a choice, not unlike the read option. While more experienced lines (and more importantly, more experienced QBs) may identify Kovacs lined up at the 7-tech position, this sort of blitz still puts a remarkable strain on the offense.
Imagine if teams begin to anticipate this stunt maneuver and cheat the play. Michigan can simply send Kovacs/blitzers directly upfield on the weakside of the play. Or, as you'll see later today, Kovacs could drop off into coverage and force an errant throw by the quarterback. The endless tinkerings of a defensive genius.