Chris Ash and Ohio State's Ongoing Struggle with Cover 4: Part II

By Ross Fulton on March 18, 2014 at 1:15p

So if Chris Ash's job is to properly install cover 4 as the base Ohio State defense, what will it look like?

Ash begins his implementation of the coverage by starting with quarters' purpose, along with its strengths and weaknesses.

Cover 4's strengths and weaknesses

Ash's then works to utilize cover 4 in a way that allows his defense to benefit from the coverage strengths while minimizing the weaknesses. To do so, he deploys four primary calls within cover 4: Four; Cathy; Cleo and Cloud. Each call is made by the secondary based upon how the offense aligns. 


Four is the base call against a pro-style formation; i.e. one with 21 (2 RB, 2 WR, 1 TE) or 12 (1 RB, 2 WR, 2 TE) personnel.

Four versus 12

With Four, the corner plays what amounts to a loose man to man. To take away the quick passing game, the corner can play press coverage and use a bail technique, quickly getting depth post-snap.

The safety sits flat-footed at 10 yards and reads the No. 2 (inside receiver) to his side of the field. The safety and outside linebacker work in tandem coverage based upon what the No. 2 receiver does.

If the inside receiver releases vertically, the safety takes him in man and the outside linebacker quickly gets outside depth to defend curl to flat. If the inside receiver release outside within five yards, the outside linebacker will cover him in man coverage and the safety will play his quarter zone and looks to help on the outside receiver.  If the No. 2 receiver crosses inside, the safety and outside linebacker passes him off to the inside linebackers and play their deep fourth and flat zones, respectively.

Four Call

The combination coverage rules demonstrate the mixed nature of cover 4. It is a matchup zone that requires extensive amounts of man coverage from the back seven defenders, but also pattern matching and proper communication.


Cathy is utilized by Ash against spread formations, namely when an offense has two or more detached receivers to one side. Ash describes it as a "soft pattern read."

With Cathy, it is the corner and safety that work in tandem to read the release of the No. 2 receiver to their side:

  • Outside Release < five yards -- Corner takes the flat; safety works over the top of the outside receiver, and OLB drops to hook to curl;
  • Inside Release -- The corner takes the outside receiver in man while the safety plays his zone and looks to bracket the outside receiver;
  • Vertical Release -- Corner and safety take No. 1 and 2 in man coverage.

The corner and safety also have rules for the specific combination patterns of china and scissors.

  • China (aka Smash) -- The corner sinks to help the safety with the corner route while the OLB (or nickel) quickly extends to the smash route.
  • Scissors -- The corner and safety trade off the crossing receivers.
Cathy vs scissors

In sum, the corner, safety and outside linebacker work in combination to play man coverage against distributed patterns within their zone, taking care to be aware of particular route combinations that are used against cover 4.


A Cleo call is made between the safety and corner when the offense has two detached wide receivers with a minus split or stacked alignment.

Cleo is not necessarily an independent concept. Instead it is a version of Cathy with one adjustment. The difference between Cleo and Cathy is that the corner and safety use an in and out concept where they will pass off the inside and outside receivers regardless of depth.

Again, the goal is to respond to methods offenses use to attack cover 4. Offensive coordinators look to confuse cover 4 defensive back reads by having receivers switch or cross. Offenses tend to do so from such stack alignments. Cleo is a preemptive measure to more easily have the corner and safety trade off receivers that cross their zones.

Cleo v. Switch


Cloud is the final tag Ash uses with Cover 4. Cloud is actually an amalgamation of cover 2 and cover 4. With cloud, the outside linebacker or nickel -- and not the safety -- will cover the No. 2 receiver with man coverage if he releases vertically. The safety then plays a deep half zone.

Cloud is used against 2 x 2 shotgun formations away from the offset halfback to avoid giving the offense an easy flat route completion to the No. 3 receiver.

Cloud is a change-up, preventing an offense from assuming the safety will cover the number 2 route vertically without deep help. With cloud, the defense will now have a receiver playing man underneath the receiver with the safety robbing over the top, providing the potential to create turnovers through confusion.

Mix and Match

The coverage calls are not separate concepts but can be used in tandem. The corner, safety and outside linebacker to each side of the centerline work as a unit independent of their counterparts to the other side. Each side uses the call that responds to what the offense presents to their side of the field.

For instance, if the offense aligns in the shotgun with 11 personnel (3 WR, 1 TE, 1 RB) the defense will play Four to the tight end side and Cathy to the detached 2 WR side.

Cathy and Four

This allows the defense to best defend what the offense is most likely to attempt within a given alignment.

Again, Ash's coverage tags work towards the same purpose. As discussed, Cover 4 allows a defense to easily apply safeties against the run while deploying a match-up zone that utilizes ample amounts of man coverage. But like any defense, Cover 4 also has its weaknesses. Ash's coverage tags are a recognition of those weaknesses and an attempt to minimize them by flexibly adapting to what is presented by the offense.


Comments Show All Comments

German Buckeye's picture

Glad I don't make a living out of deciphering those hieroglyphics...great job as usual Ross.


+7 HS
johnny11's picture

Nice write up as always. Thanks

Killer nuts's picture

Ross, I love what you bring to this site

vitaminB's picture

Cover four, that's gotta be twice as good as the cover 2 right?

+16 HS
avail31678's picture

Yeah!  We should totally go to a cover 11.

+11 HS
Fugelere's picture

Anything is better than the defense from the previous two seasons which seemed to be the cover-nobody.

+8 HS
lsjSnail's picture

Yeah, Cover 0 is not very effective.

+6 HS
Seattle Linga's picture

It's either super late or you guys just made me laugh out loud - thanks for the chuckles

+1 HS
Ashtabula's picture

Great write-up.  Here is what worries me about cover 4 with this year's team; inexperience in the defensive backfield since pattern matching is easier said than done and lack of a stud mike linebacker since they must be able to "clean-up" the mistakes of others, especially when playing from a 4-3 base.

Killer nuts's picture

I think the type of guy we have been recruiting to play safety (Bell, Burrows, etc) will be much better cover guys than what we have had and will fit this system well

DC-town's picture

Great read Ross- some of it is over my head so ill have to circle back on this article again.

It will be nice if we have an athletic strong and weak side linebacker for this scheme, good if that turns out to be Lee, I don't know about Perry covering a TE or receiver in the middle of the field, but we'll see

'Piss excellence' -RB

+2 HS
RBuck's picture

What I got out of this is that we need some fast-ass safeties.

Long live the southend.

+1 HS
sivaDavis's picture

They just need to react well. So be smart and take in all Ash has to offer. I wouldn't worry about the speed aspect, we got that.

"I've had smarter people around me all my life, but I haven't run into one yet that can outwork me. And if they can't outwork you, then smarts aren't going to do them much good." - Woody Hayes

sivaDavis's picture

(Double post)

"I've had smarter people around me all my life, but I haven't run into one yet that can outwork me. And if they can't outwork you, then smarts aren't going to do them much good." - Woody Hayes

BrooklynBuckeye's picture

Thanks, Ross! Really great stuff. This hammers home how important post-snap reads are on defense. I hope we have a future Mike Doss-type Safety back there. This also helps explain why losing Christian Bryant last year was so devastating. You can be a leader on the sidelines, but that's what coaches are for. Teams need leaders on the field, to keep guys focused and on the same page, especially against hurry-up offenses.

d5k's picture

Is it fair to say that the quarter-quarter-half simplified defense OSU deployed against spread teams with Roby on the boundary was similar to Cloud to Roby's side and "Four" to the other side?  And you have mentioned before that this had more to do with run defense than pass defense I believe?

The ability to dynamically adjust coverage to the formation/alignment of the offense seems especially important vs. the hurry-up.

Fugelere's picture

 So I take we're still going to run this coverage from the under front in the base 4-3, or will we switch to the over like MSU?

Ross Fulton's picture

Good question and remains to be seen. I personally think we will become more of an over team, but we're all guessing until we see what happens this Spring.

theopulas's picture

did anyone else think that was alot of thinking before the play and chance for mistakes after the snap for 20 year olds...


buckguyfan1's picture

When all else fails, call Raekwon Kill the Quarterback. 

+1 HS
theopulas's picture



+2 HS
allinosu's picture

From the sideline?

CentralFloridaBuckeye's picture

Great work Ross!  You're the man!  I hope that these plays help lead the Bucks back to the days of the Silver Bullets when the D was one of the best in the nation.

Go Bucks!!

BeijingBucks's picture

Ok so perhaps not being a 20 yr old agile thinker I see two glaring weaknesses to this.... One, your defensive leader (which is who?) has to be able to scan the O, filter the misdirection crap, and call the right iteration so everyone hears it?

two, the hand off of coverage, especially from CB to LB scares me... And number the next one, this all happens in 1-3 seconds. 

I think I will stop being quite so hard on the defense facing today's crazy offensive packages. This is absolutely about how good the coaches are at teaching pattern recognition and unconscious responses. Aka reps. I'm worried all over again for this year.......

None can love freedom heartily, but good men; the rest love not freedom, but license. ~ John Milton

Mighty Mike's picture

Thanks as always Ross. Do you think the usage of Lee at the W (walk-out?) means that OSU will simply stay in the base formation or will like last year Perry will be replaced by the Star (Burrows?) and OSU? 

gm3jones's picture

So how effective would draws and speed options be on this? I am seeing alot of LB read and reacts and if we play an option team, that could leave our LB flat footed (or confused) and vulnerable. Also, which position would be the QB of the group on D? Seems like a smart safety or Mike LB.

There is nothing more remarkable as learning to think better.

d5k's picture

Play action and the extension to packaged run/pass option plays are the main kryptonite to pattern matching along with the switch routes Ross talked about.  Trying to expose the safeties reacting to the run game (they are basically playing a 9 man box vs. the run and a soft 7 man box vs the pass in theory) and confusing the reads.  In 2012 our safeties would not only overreact to run fakes, they would over-run run plays to the outside, taking bad angles, and leading to Bigelow's multiple trots down the sideline.

+1 HS
gm3jones's picture

That is what I was worried about. So we need a "heady" LB and Safety to be able to properly react to these kind of plays. SO we would run  cleo adjustment with these kinda of teams then?

There is nothing more remarkable as learning to think better.

OfficerRabbit's picture

Sort of off topic Ross, but considering the way in which you can "read" and "decipher" different formations and plays, does it ever take away from the overall experience when watching a game?

I picture myself pulling my hair out when we let a busted play get us, and I see you calmly sitting there moving around X's and O's in your head, identifying the culprit (or culprits if we're talking last year).

Great write up (and informative) as usual!



bull1214's picture

and remember that ash's way is supposedly a more simple concept than most. maybe now some of you can appreciate how easy it is for a player to be out of position during a full speed game.......

Dougger's picture

Hopefully these changes bring consistency to the Silver Bullets.

Ross in your previous post you mentioned how this backfield dictates the rest of the defense. Do we know if/how cover 4 will affect Larry Johnson's teaching of the front-line? My presumption is that he would say get after it no matter what. (also, does anyone know if PSU used cover four in their defenses with Larry?)

Go bucks

I like football

Brutal Brutus's picture

Coach Fickell - "Sh*t, this guy brought plays..."

Fear the Nut...

+1 HS