Friday, September 17, 2010

Notre Dame and snap counts

Ed. note: In lieu of a UMass preview, something that, unless something awful happens, should be useless, I wanted to do a little breakdown of Notre Dame's defensive line shift that was effective because of Michigan's predictable snap count. For a comprehensive UMass preview, visit MGoBlog.

I mentioned in Wednesday's Good Idea, Bad Idea post that Michigan is continuing to use a predictable snap count. When I was watching the game live, I saw Notre Dame shifting their defensive front right before Michigan snapped the ball, and finally found some video of comparable plays that shows that it may actually be more detrimental to the team's blocking schemes and production--aside from the obvious: allowing defensive teams to time blitzes--than originally thought. First up is a play in which Notre Dame uses the defensive front they originally showed:

Here, Michigan is set up with Denard in the shotgun and Michael Shaw to his right. They're using an H-back (Martell Webb) in this formation. Notre Dame is in the 4-3 base set that they had shown for most of the game. This will eventually be a passing play, but the important thing to watch is the blocking of the offensive line.

After the snap, Denard rolls to his right. David Molk and Patrick Omameh double team the strongside defensive tackle. Perry Dorrestein has one-on-one blocking against the strongside defensive end. Mark Huyge is charged with blocking the weakside defensive tackle and Steve Schilling is being given a free release into the second level. Martell Webb is supposed to get to the second level and block one of Notre Dame's corner backs as this will eventually be a counter screen pass to the weakside of the field. The weakside defensive end is unblocked.

Regardless of how this play ends, you can see that the offensive line is tied up with their appropriate defensive players. Huyge has passed the weakside defensive tackle to Schilling and is releasing to help block on the screen pass. Omameh and Molk are still driving back one of Notre Dame's defensive tackles. How the play ends is beside the point (it ends poorly, for the record). But you can see that there's order. All of the offensive linemen know where they're supposed to be and who they're supposed to block.

In the next play, Michigan is in the same formation and, at least initially, Notre Dame is in the same defensive formation. But because of Michigan's predictable snap count, Notre Dame was able to change their defensive front just before the snap and confuse the offensive line.

Here you can see that Michigan is in the same alignment they are above. Denard is in the shotgun with Michael Shaw to his right. Martell Webb is in as an H-back. Notre Dame is showing the same 4-3 defensive front. But because they're able to time Michigan's snap, the defensive line shifts from a 4-3 to a 3-4, changing all of the blocking schemes for the offensive line:

As you can see now, Notre Dame has shifted into a 3-4 front with the weakside defensive end becoming a stand-up linebacker, and the rest of the defensive line shifting over so that now they have a nose tackle and two defensive ends. Worse still is that all of this happens with Molk's head down, waiting to snap the ball; when he picks his head up, he'll be greeted with a completely different defensive front.

Because this is a different play than the above example (this is a designed QB run), there will be some differences in how it plays out. But the important thing to watch is the offensive line. If Notre Dame was in a 4-3 front still, Molk would've reach blocked the strongside defensive tackle with Omameh, Dorrestein would've seal blocked the defensive end, and Michael Shaw would block the playside linebacker. Instead, Molk goes for a reach block on the defensive end who has taken place of the defensive tackle. Omameh looks to double team the defensive end and Dorrestein, who was able to see the changing blocking schemes, also hits the defensive end and then releases to the second level.  Long story short, there are three linemen blocking a single defensive end. The nose tackle is being left unblocked by the front line and is now the responsibility of Webb, who is supposed to release to the second level to block one of the middle linebackers (about more which later).

The next thing you see is utter chaos. Molk and Omameh and still tied up double teaming the defensive end. Dorrestein and Schilling have released to the second level to block linebackers, and Huyge is tied up with the weakside defensive end. Shaw is locked up with the playside linebacker. The nose tackle is going completely unblocked and is able to, along with the playside middle linebacker, keep contain on Denard and force him back into the defensive help.

More chaos. Denard has no where to go and is being forced back into unblocked defenders. You can see the nose tackle in the middle of the scrum without a single Michigan player looking at him.

Denard has to cut the play back, and runs into the defensive end that Omameh and Molk were supposed to double team. The nose tackle still hasn't been touched.

This is admittedly a bit of a convoluted example, but the evidence is clear: when Notre Dame was switching defensive alignments just prior to the snap, the offensive line was confused, missed blocks, and didn't know its assignments. We've already seen Michigan State time Michigan's snap count to devastating effect, and if Michigan doesn't change their count, problems like this will continue to arise. Notre Dame has question marks on defense and was able to confuse Michigan's offensive line. Similar moves against Wisconsin, Ohio State, or Penn State could crush Michigan this season.


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