Neck Sharpies: Air Force’s 50-Slant Defense Comment Count

Seth September 20th, 2017 at 11:54 AM

I thought Air Force had a very good defense. They weren’t big or super fast, but they were smart and sound—if a defense as a whole could get a nickname I’d call them Ol’ Eleven Kovacses.

Their gameplan was also brilliant. They knew Michigan wanted to run inside the tackles, get Speight some confidence, and get athletes out to the edge, so Air Force came in with a plan to jam up running lanes and make Michigan try to guess where the big hole would be. This is AF’s look on Michigan’s first running play:


They’re in base 3-4 personnel, with both ends lined up in 5-techniques (over the tackles’ shoulders), both OLBs in 7-techniques (over the TE or hypothetical TE’s shoulders) and one safety down at linebacker depth to react to Michigan putting a lineman (Ruiz) at tight end.

Now this is not Belicheck’s mother’s 3-4. That nose tackle was 5’11/260. He certainly wasn’t going to be two-gapping. Rather out of this setup Air Force’s plan was to have the nose attack almost like Brown’s 3-3-5 linebackers, appearing in any A or B gap on any given play and making life hard on Michigan’s inexperienced interior OL to figure out what to do with him.

If that all sounds familiar, it’s because you’re old, and it is:

That’s right: that sonovabitch Calhoun walked into Michigan Stadium and tried to run Bo Schembechler’s defense on us.


[After the JUMP: The 50 slant, and picking holes in it]




beef-to-speed spectrum in play. it’s “50” because 5 men on the line, center in a 0-tech

This defense is similar to Don Brown’s 3-3-5 in that it’s a gap defense like a 4-3, where each player has a gap they can focus on rather than reading and reacting. Also like the 3-3-5 it expects to be using lighter players and makes up for that by surprising you with which gap they’ll be in. They both use a smallish nose for that purpose. The 50 slant is an extremist in this regard—rather than using a linebacker as a surprise fourth DE, they’ll have their defensive linemen constantly slanting into gaps they didn’t line up over.

The key is that nose tackle. You know the story of Donnie Warner? If not, imagine Rudy was about an actually impressive person rather than a con artist who played one garbage down. Donnie was about the size of Mike Hart and played nose guard for the stoutest defense in the country. Interior OL in the mid-’70s were about 250 so if you’re trying to imagine Donnie today imagine Devin Bush playing nose tackle. This was the basis of one of the great Michigan defenses of all time.

Donnie would line up in the middle of that defense and read subtle cues from the offense to guess where and how he should attack each play, and communicating that to his teammates. He was a master at reacting—shoving the holes next to him closed and refusing to give up ground, often taking two linemen out each play. If you tried to double him and attack inside gaps, well, the other linemen were slanting into those all the time. Meanwhile the strong safety, which Bo called the “Wolf”, would be hanging out where Don Brown puts his viper, and cleaning up in much the same way. It was really really hard to run on Michigan—you basically had to guess where they weren’t slanting, and hope you didn’t give away your intentions when Donnie started reading you.


Slanting in the gap defense sense of the word means to twist gaps between your DL and LBs. Let’s envision a super-basic 3-4 front:

image image
                      normal 3-4                 hard frontside slant

The gap assignments are what you’re lined up over. But everybody changes their fronts up a ton, because if you don’t you become easy to attack. One tried and true curveball to throw an offense is to have the DL all angle over a gap or more after the snap and the linebackers then “scrape” to fill the abandoned lanes. Same look before the snap, but after it the attackers are not where you expect them to be.

The point is you have to cover all of these gaps but you can only stuff so many of them with linemen (or blitzers, Don Brown adds), because you need some of your front to be in coverage.

You don’t have to slant every guy, in fact it’s more common to only do it with one or two pairs. Here’s a canonical slant from Indiana last year:

A lot of the cat and mouse games that offenses and defenses play are changing gap responsibilities, trying to put an immediate attacker—either a defensive lineman or a blitzer—into the offense’s preferred running lanes. The offense in turn tries to run where there are more linebackers.

Here’s a play from later in the game where the defense’s slant guessed correctly.

Michigan there is running inside zone. Air Force has a subtle frontside slant on. Again, I think they’re shifting the direction of this with motion:


Note how like with Don Brown’s defense the three defensive backs are rotating when McKeon motions from that three-back look to a 2TE front. Also note that Air Force has 8 1/2 men in the box. It’s hard to run off-tackle when there’s a defensive back plowing into the tackle at the handoff:


To keep Michigan from just going long on those run-focused safeties, Air Force played their corner off the receiver. Michigan had the option of easy yards with quick passes to the receivers, but taking easy yards wasn’t the gameplan, for one, and two Air Force expects that and their DBs were reacting very quickly to it.

No, the way to beat this stuff is Western Front style: find the hole they left you by moving too much material to where they think you’re going, and bust a hole through. It’s not pretty; in fact until you do beat them through the soft spot it’s going to be a long stalemate.

On this play, a quick backside attack off Ulizio and Onwenu was likely to find soft linebackers getting devoured like so many grapes. By the time Isaac realizes this and is cutting back to it, those linebackers have been able to rally, and the overhang cornerback is in position to run up into the gap. The Mike woops Onwenu, the DB comes up, and this is a minimal gain:


Inside zone is built to attack the gap that shows, but it also reads outside-in, and by the time you’re cutting back the defense has an opportunity to get reinforcements to the line. You can beat anything by simply kicking ass—the question here is how to put the players in position to do so. So let’s go back in time and see what happens when Michigan did choose the right gap.


On this one (again, possibly a check due to the McDoom jet motion), the nose slanted into the frontside “B” gap, with linebackers now accounting for both A gaps and the backside B. They’re expecting Michigan to run to the side with Ruiz as a tight end and McDoom as a potential ballcarrier and Hill lined up like a shock panda, and they’re further convinced when Speight’s path to the ballcarrier is that direction.


Michigan actually came out passing and play-action passing, perhaps to see if they could get a sense of how Air Force was going to set up against the run. After picking up a [pours one out] first down on Tarik Black’s great sideline catch, they ran their first run.


Sorry it’s hard to see all of those arrows. Michigan correctly guessed that Air Force’s response to overloading one side then running jet motion that way would be to roll the coverage and slant to the frontside. That puts a nose tackle immediately in the frontside B gap that a power run would love to attack, and in case of jet the free safety is coming down ready to make it a short “Doooom”.

With the backside DE twisting with the WLB that leaves three linebackers for the inside gaps to the backside that this play attacks. Twisting the WLB inside on this play is like showing up to a surprise party at the same time as the guest of honor. Surprise! Thwack.

Still the room here is created by the DL abandoning the backside, allowing Bredeson a free release into both linebackers. Bredeson pops the Backer (B)* at the 40 yard line…


…getting the unblocked MLB (M) stuck behind that so he can’t make a tackle attempt on Isaac. Isaac is now getting up to speed, which for him is plenty to squirt through the gap created by Hill’s block and Cole’s kickout.

And here’s the last piece: with the safeties playing up to cover run gaps, they’re not in position to keep this down. That’s a rotated cornerback playing midfield when Isaac burst through and is heading downfield at plaid speed. After two bad steps upfield the cornerback just baaaaarely gets enough of Isaac that his foot falls a centimeter out of bounds.


A tip of the cap to Air Force: Calhoun had a great gameplan for Michigan (and a highly apropos one) that was a good fit for their personnel. The whole point of their defense was to make Michigan’s running game an all-or-nothing prospect. Michigan had to guess each play where the soft spots would be, and if they chose wrong there were 9 potential box players ready to stuff for no gain. Michigan’s backs on occasion missed some of those breakthrough points that the coaching found them—I’m sure the UFR will highlight a few of them, though often those gaps were waaay backside cuts that you don’t normally expect to be there. The point is don’t be too hard on the running game for not blowing a Mountain West team off the line, and certainly don’t be hard on Michigan’s coaches. Air Force made it hard.


* [Everyone has different terminology. I like to call the second middle linebacker in a 3-4 the “Backer” because it makes labeling easier. A lot of 3-4 defenses call him the “Will”, since he’s similar to a 4-3 WLB, then make up a cool prospectin’ name for their weakside LB. That is easier on players but more confusing in diagrams.]



September 20th, 2017 at 12:07 PM ^

"Michigan had the option of easy yards with quick passes to the receivers, but taking easy yards wasn’t the gameplan." This right here is a swift kick to the groin.


September 20th, 2017 at 12:34 PM ^

I noticed on plays after Michigan took the short stuff, AF brought their corners up from 7 yards off the LOS to 2-3 yards off the LOS. It's like they were saying, you got us once, you aren't getting us again. They were constantly changing up looks. And that one linebacker they had was really quick to the ball.


September 20th, 2017 at 1:07 PM ^

If the defense is giving you enough to keep moving the chains, take it.  If they have to react by moving up the DBs, you have won; if having the DBs 2-3 yards off the line of scrimmage wasn't contrary to what they wanted to do, they'd have been there to begin with.

Personally, I think Michigan didn't take the "easy" yards because a slightly off-target throw there is six the other way.

Space Coyote

September 20th, 2017 at 2:09 PM ^

But the same applies here. If you don't rep the play you are asking for disaster. A CB 7 yards off can easily pick off a bubble. The WRs need to know their reads and blocks and the coverage and the WR needs to get it out. I think the coaches are repping other things they believe are more fundamental to their O. Argue if you want that they should be practicing bubble instead of other things (within the scheme of their O inside with the coaches), but if they aren't ripping it the answer isn't draw it up in the dirt.

Space Coyote

September 20th, 2017 at 2:52 PM ^

And that's a point that needs to be brought up, because they use other methods (like the ones you noted) to attack horizontally (Borges wanted to use bench routes from the slot rather than bubble because that's what they'd repped, by the way, so your point is significant then as well). But I think they've also had some mistakes trying to run those things this year and they have been held down this year too. They've been implemented for very specific looks because they aren't spending the time to implement it and rep it for everything. I don't believe the coaches just aren't doing it because gameplan. If it's in the playbook they'll take what the D gives. It's that they aren't confident in the execution of the play because the young guys haven't ripped it vs all looks

Space Coyote

September 20th, 2017 at 2:53 PM ^

Which is generally my point. There is more to it then just "CB is 7 yards off, throw it", and you have to be confident in the execution. I love the extended handoff, think it's one of the best plays to have readily available, but still need to have the reps to be confident in the execution vs the defensive look.

The Maizer

September 20th, 2017 at 12:31 PM ^

Is this something Air Force is uniquely equipped to do (either through personnel or preparation)? I.e. are other teams going to try to follow this blue print to make it tough on our offense? Or they won't try it because the soft spots/large holes are too big of a risk for ordinary defenses to take?


September 20th, 2017 at 12:52 PM ^

Strategically yes tactically no. Cincinnati had a very similar approach but they just did it by beefing up on the line and playing a 4-3 under almost like a 5-2 eagle. That was less about surprise and more just gambling everything on the defensive line not getting beat up. badly coached.


September 20th, 2017 at 12:38 PM ^

May be a dumb question: Does Mason Cole have to report as eligible for this play since he's first guy from the outside on the LOS while wearing an ineligible number? Or do you only have to report in the NFL?

EDIT: The more I look into it, this link makes it seem like it's illegal. And that none of the 5 OL with ineligible numbers may be lined up as an eligible receiver, even if not going out for a pass. That the only way to make it legal is to switch jersey numbers. In our case, Ruiz came in with an eligible jersey # but is lined up ineligible (with Crawford covering him) while Cole has an ineligible jersey # but lined up eligible.


September 20th, 2017 at 12:56 PM ^

Correct. Michigan has one fewer eligible receivers here because of Mason Cole's number. In college it's not about reporting you just have to have the right number and be lined up as an eligible receiver to be an eligible receiver. There is a lineman number rule but I forget why it doesn't apply to covered receivers.


September 20th, 2017 at 12:39 PM ^

Against this type of defense, is it better to have some patience as a running back to find where the soft spot is? I know Isaac hesitated once on a 3rd and 1 and it buried him, but during 1st or 2nd and long is that something to try or does that just make for more TFL?

People seem to applaud Leveon for his patience, so I am curious.


September 20th, 2017 at 12:59 PM ^

Generally patience is good but it depends on what offense you are running. Power and Zone are best when you set up your blocks, require patient runners. ISOs are more about blasting forth. However the longer you wait against a stacked front the more time those safeties have to react and those linebackers have to get off their blocks. You want to see where the Gap is and hit it when it's there. Patience matters because it's not always there right away


September 20th, 2017 at 1:42 PM ^

their LB play is not very good. On the first the backside backer who Onwenu wiffs on doesn't move until a couple of seconds after snap. Onwenu in zone blocking needs to chip the NT and move to the second level. If hetakes the proper angle it's an easy block and that hole now becomes bigger and it's a one on one matchup between Issac and a safety and I will take that every time. Issac should gain at least three yards and if he breaks a tackle maybe goes to the house, but a slow reacting LB should amount to a bigger gain.


The second one the LB's basically run into each other. The playside backer needs to immediately fill that gap and take on the block, plugging it up and the backside then slides over and reads and reacts to the play. They seemed to be all over the place in the game but looking at these clips it's actually poorly played by them, we should've had more success on a zone scheme and an OL getting to the second level or our FB. For an aggresive D the LB seem to play a little too passive more read and react rather then fill.

Space Coyote

September 20th, 2017 at 2:14 PM ^

The more aggressive the D the less patience you require. Like you said, generally it's good, but in this case it's good until you see daylight and then you have to hit it. You're not trying to pick through the wash, you're trying to find a crease and break through the wall into the second level. Catch guys on the wrong side of blocks or enough out of position and then you have a lot of grass (this generally applied both to run and pass)


September 20th, 2017 at 1:08 PM ^

I think we'll see a lot more teams stacking the box with 8 or 9 players in hopes of completely stuffing the run or being able to get pressure on Speight.  This, coupled with the fact that most of our receivers aren't getting a whole lot of early separation and Speight's inaccuracy when pressured, has led to many stuffs at the line and horribly thrown balls to receivers.  With this in mind, defenses will pin their ears back and tell Speight to beat them (especially in the redzone).  I bet if we could start connecting on some decent quick-hitters in those situations, it would cause the defense to back off a little.  Hopefully we'll be able to see some of this execution and start softening up the defense to actually be able to see what this offense is capable of.


September 21st, 2017 at 9:23 AM ^

Okay.  What I thought you meant was that teams have not been reluctant to stack the box against Michigan because they haven't had reason to fear giving up long passing plays.  

Of course, that isn't true because M has been consistently able to generate big plays in the passing game since at least the middle of the 2015 season.  Perhaps Speight's accuracy issues against Florida and Cincinnati emboldened Air Force to play the run more aggressively (though I tend to think that just happened to be their plan all along), but even if that's true, it hasn't been a consistent issue under Harbaugh.

But evidently you meant something different by your "afraid to stack the box" remark.  I haven't the faintest idea what else that could mean.  So please explain: if you were not suggesting that Michigan's supposed inability to punish teams for overplaying the run with big plays in the passing game has made opponents unafraid to stack the box against Michigan for years and years, then what did you mean?


September 20th, 2017 at 8:51 PM ^

I think the experience of the WRs allowed them to get open quickly and Speight knew what to expect with them.  Speight and the new WRs haven't shown that chemistry yet (outside of Perry) and that's what we're seeing now with this offense.  Last year the teams with good front sevens just tried to do whatever they could to overwhelm the line in order to take away all rushing opportunities but Speight was able to mitigate that some due to his familiarity with the WRs we had.


September 20th, 2017 at 9:25 PM ^

A lot of stacked boxes are due to our formation. The more guys the offense has in the box, the more guys the defense puts there as well. Just because there are 8+ defenders in the box doesn't mean defenses don't respect the pass. Most of the time it's simply having enough guys to account for the number of blockers the O is bringing.


September 20th, 2017 at 1:38 PM ^

Another thing people didn't really mention after the game which I think was very valuable is that Air Force had a bye-week leading up to our game. They played a horrific VMI team in week 1, then had 2 full weeks to prepare for Michigan. Props to Calhoun and his staff for having an excellent gameplan. Major props to Don Brown for instilling some of the triple-option looks over the summer and then really dialing in the week before the game. 

Cranky Dave

September 20th, 2017 at 1:46 PM ^

play from 1:13 of the 3rd quarter the line actually did a decent job of blocking, except for Onwenu whiffing on the LB.  Cole got a nice kickout, and Bredeson, Kugler and Ulizio all take their guys right down the line in the direction the DL was slanting.  All Onwenu had to do was get in front of the Mike and seal him inside.  It looked like Isaac would have gotten 4 yards before the safety arrived.  Unfortunately all it takes is one missed block to blow up a play.