Picture Pages: More Throwing Rock

[Sorry about the delay. Internet issues this morning.]

To continue a theme on Michigan's suddenly mediocre run game: dude, it was all Purdue's cover zero approach. Here's a play that's beautifully blocked all around and still ends up with meh results. It's Michigan's final drive of the first half; the Wolverines have the ball first and ten on their own 43.

Standard three wide from Michigan; Purdue moves their nickelback over the slot receiver and has their safeties in that no-mans-land between deep and shallow:

By the snap they're still in that shallow range; the deeper guy is only seven yards off the LOS—that's where WVU's stack keeps its middle linebacker. Michigan's going to run a stretch:

As usual the key block is the one in the center of the field, where Schilling and Molk are working to seal the playside DT. you can see above that the playside DE is not slanting inside this time and will get kicked out. Michigan is doing something weird, though: they are blocking the backside end. They've done this a lot this year but in almost all cases they've done it on inside zone plays where a cutback is one of the main ways to gain yards. On a stretch this guy is usually set free to fruitlessly chase.

At the mesh point Robinson gets contain from the safety no jk lol linebacker and hands off. Molk has already gotten across the playside DT, who is dead:

That is a dead DT. With Lewan getting a kickout Smith will have a hole to cut into. Schilling releases downfield and gets a good block on the playside LB; Koger heads outside and pulls the other safety no jk lol lb with him. Hurray yards?

Yes, but issue in the middle of the field wearing #45:

This linebacker is the guy Huyge would have released into if he wasn't blocking Kerrigan. He's totally unblocked and can run down the line as Smith zooms past dead DT and Omameh drives the backside guy yards downfield; Schilling and Koger have picked up eliminating blocks on the other LBs.

Through the hole, Smith is one on one with the LB…

…who tackles.

The end result is a play where all six Michigan offensive linemen get blocks between good and great… and Michigan gets six yards.

Video:

Object lesson type objects:

• Generic stretch stuff. This is another example of how the stretch usually works when it works: Molk seals that DT, Lewan kicks the DE, Schilling releases into a linebacker, a lead blocker takes another one outside, and running back hits a big gap.
• Cover zero problem reinforcement. In this particular instance blocking that backside end is a bad idea, but with eight guys in the box Michigan knows they'll leave contain to a safety and send Kerrigan tearing down the line. If Smith has to cut behind Molk he will be swallowed at the LOS. There's a nonzero chance Kerrigan manages to grab Smith from behind even if the blocking plays out like this. Michigan has a choice between leaving the MLB free or leaving a guy they know will crash down the LOS free. In this particular instance getting a block on the MLB, even a crappy-push-by-the-RB-forcing-a-cutback block, is a touchdown unless Smith gets run down from behind.

  The fundamental math is still the same: there is going to be an unblocked guy in the box and Purdue can slant and shift its defense in an effort to get the ballcarrier to an unblocked guy. On the previous example Purdue did this effectively; here they hang on by the skin of their teeth but do get it done.

• Weather allows cover zero. BWS did a post on Michigan's only successful gotcha play, the fourth quarter completion to Kevin Koger that jump-started Michigan's final touchdown drive and was so wide open Denard could throw a wobbly underthrown duck and still have it easily complete. The pass on that play and about a dozen other hilariously misthrown balls by all four quarterbacks goes a long way towards justifying Michigan's resignation to pounding its head into the wall repeatedly. I'm sure Michigan won't do this again—not that they'll have an opportunity against Wisconsin and Ohio State, two teams that won't run cover zero much if at all.