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Football University - Defensive Theory

Welcome to the first day of Football University.  The course you are here for is "Xs and Os".  I am hoosierteacher, and I will be your prof for '08 semester.

Now let's get a few things out of the way, shall we?  Everyone have their books?  Good, good.  Everyone have their, what?  You there!  Yes?  I see.  No, this is X's and O's.  You are looking for "Football Law".  That class is taught by Trinidad Jack on Tuesdays and Thursdays.  At any rate, Dr. Jack Jusris Doctor is seated a couple of rows in front of you auditing this class, so you not only have the wrong day but the wrong place.

Good heavens, what are they sending me nowadays?

Ok, might as well get going.

Introduction to Xs and Os

First, we have some little rules to help us define our terms as we proceed.  These are not enforceable, but are recommended.

  1. The offseason should be called the reloading season for the purposes of this class.
  2. I give extra credit to those who do not capitalize the words "oakland" and "raiders".
  3. All questions in good faith are valid.  We have some folks that are hardcore fans, and some folks just learning the game.  I will address all questions, and of course the scholars in this forum are invited to help each other out as well.  
While I am the prof here, the truth is many of our attending scholars are profs in their own areas and have a better grasp than I do of some concepts, or perhaps a different view worth considering.  I will hold the lecture, then the discussion is free form for all who want to take part.

In short, I will present a topic each week.  It can be a topic I've developed, or a topic someone has brought up that they would like to see addressed.  In the comments section you can ask questions, answer questions, or discuss the topic.  Heck, you can even discuss a different topic if you want.

Here is a comment from another story that sums up what this class is all about:

"Things I want to know more about.

Different defensive strategies, such as cover 3 zone, Tampa 2 zone, cover 2, bump and run. What makes them successful? Why do they fail? What kind of players do you need to run each defensive scheme?

I want to know more about gap assignments and different ways defensive linemen are instructed to play by their defensive coordinators.

I would love a brief west coast offense 101 session so I can know more of the basics about the offense that I don't already know.

I would also like to hear your thoughts on what you look for when seriously evaluating players.

Those are just a few things for now.

by Make It Rain on Sun Feb 03, 2008 at 05:56:05 PM EDT"

Excellent.  I will be getting to those in the weeks to come.

Before I continue, many, MANY, MANY thanks to Styg50 for his help in showing me how to post images and create diagrams.  Most of my current and future work at MHR would not be possible were it not for his patience and much of his valuable time.  I am in his debt, and much of the credit for the quality of my posts should go to him.

Now click on the "read more" link below so you can read the full article for today's class.  See you below the fold!

Todays lecture:

Defensive Theory.  Philosophies of defensive theory, current applications, and the march of defensive theory from the start of football to the future.

This is a good place to start, since coaching defense was my bread and butter.  The ideas below are from a seminar I attended for high school coaches, and was taught by several college coaches from around the country.

What is the underlying philosophy behind football defense?  The answer is that there is no unifying philosophy.  One coach may say that preventing the opponent from scoring is correct.  Another coach may jump over the first coach to point out that preventing the opponent from outscoring your team's offense is a bigger consideration.  Yet another coach will say that preventing yardage is most important.

So I want to introduce you to a concept that will spring up again and again in our series:

Coaching Axiom Number One:  There is no "best" system, approach, philosophy or scheme.  There is only the superior application of one's own approach to the game over and above the opponents application of offense.


Whose kung fu is better?  Let's say I advocate system "A".  Let's say that system "A" goes up against system "B".  If system A employs a master and system B employs a six year old student, system A will win.  


But, (you might say) what about if all things are equal?  

Example established:

The answer is, "All things are never equal".  Pair up two masters with similar physical characteristics and you will still have differences.  Even if system A usually wins over system B in pairings, it can be pointed out that in football a system "C" may have the advantage over system A, which beats B.  This circular system of pairing systems is the case in football, and the idea we'll discuss further later on.

History of defense

Note the absence of a QB!

We can take a more in depth look at some of the early formations and systems used by defenses when football was just getting started, if someone wants to.  But for now suffice it to say that football was kind of like rugby.  The game was based on running, and what few throws happened were typicaly short and lateral.

Defenses placed a premium on big guys that could stop a run at the line.  Runs to the edges were uncommon in those days, and they rarely worked.  Offenses called plays that gave the gap for the runner to hit, and the supporting players on the offense (backs and flankers) hit that hole with the intention of either shoving a defenseman out of the way, or knocking him down.

The defensive line (most of the team) was geared towards wearing down the offensive by hitting the offensive linemen hard.  The "backers" were also big, but were charged with flowing to the ball to make the tackle.

Then something happened.  Something...


The forward pass forever changed football, and propelled the game towards baseball as "America's sport".

Now the flanker position vanished.  The FB gave way to the the modern QB, and WRs were created.  What's a defense to do?  Adapt or die.  Thus the defense added the present day CBs and SAFs.  The game became more fluid, faster, and complex.  Defense was no longer a game of brute strength, but a combination of strength, speed, agility, and intelligence.  Positions specialized more, and coaches had to become more than just motivators and personal trainers.  They had to plan and scheme on a deeper level.

The next revolution was big, but more subtle.  In fact, most casual fans didn't notice it.  In the late 1970's a rule change affected how the offense could use their hands and arms (they were allowed to extend them when blocking).  Again, I want to just point it out but not dwell on it.  I could spend several articles on how this radicaly changed the game.  Suffice it to say that defenses had to change a large portion of how they approached the game.

This brings us to the present day.

Philosophies of modern defenses

There are different ways that a coach sees a defense.  No coach really only uses one method, but instead overlaps.  Working with a coach at the blackboard will help you see what kind of coach you are dealing with.

Let's look at perceptions used by coaches:

The "geometric" view looks at the game in terms of width and depth.  Stopping plays to a certain portion of the field, preventing long plays, etc.  A "geometric" coach doesn't look at the players in a scheme, he looks at places on the field and then looks at how to cover them most effectively.

The "tactical" view looks at match-ups or individuals.  This coach looks at how players in a system interact, and strives to place players in a play in such a way as to maximize their potential.

The "abstract" view seeks to exploit an offense by studying the opponent, then developing plays to take advantage of holes.  Every play has a hole, and this is what the abstract view focuses on.

Now, given these mindsets, we move to the next ingrediant of defensive philosophy:  Approach

Based on how a coach views a game (see above), he now adds another layer to his philosophy.  He is either an advocate of a passive, balanced, or aggressive defense.

The passive philosophy (also known as soft philosophy) is most commonly seen in the "Bend Don't Break" approach.  Let the offense pick up yards, but only in small chunks.  The longer the offense is on the field the more chance a turnover will happen, or the more chance that a third down will fail before the opposing team gets too far.  Execution is everything, since this is also a race to see which unit can best prevent penalties.

The aggressive philosophy (hard) is seen most often in the blitz heavy approach to the game.  This approach rejects passivity, believing that there is more danger in reaction than in being proactive.  The aggressive coach seeks to dictate the course of the drive by direct influence.  This can be done by going after the QB (most common) or running a contain system that actively shuts down and funnels the play to an area of the defense's choosing (rare, but effective).

The next layer to apply is how the coach looks at threats by an offense.  Does he seek to shut down the run or the pass?  Sure, a coach may seek balance, but with limited funds he can only spend money to fill certain positions consistently better than others, and his formations and plays will leave some weakness whenever he shows strength in another variable.

Last, does the coach prefer more zones, man coverages, or containments to carry out his plans?  This is typicaly the final layer applied when a coach moves from building a team, to ownership of a system, to actually creation of plays.  All coaches mix and match, but all coaches also lean towards a favorite approach.

Classification of theory

Now we look at what a coach values on defense:  Space, time, force, or structure.

Space - Is it the gaps and the routes one looks at?  Player movement and zones?

Force - Is it pushing around the opponent physicaly to put your people in the right place to make a play?

Time - Is it precision plays with an emphasis on being at the right place at the right time?

Structure - Is it a dedication to the formation, from which (in theory) the whole of the offense can be covered?  In the other three approaches, the play creation and play calling is the source of the defense's tools, but in "structure" the formation is the play its self, with plays being only extensions of the structure (the 46 defense for example).  Contrary to popular perception, most coaches don't "favor" a 4-3 or 3-4, they base their formations on what players they have.  Rarely a coach breaks this mold (the 46 being an "everytime" example) and favors the structure over the other three considerations.

Let's look at an application.  While I advocated a certain way of approaching the game, I again reiterate that my way wasn't the "best" way.  I was good at my way, so it worked out well for my teams.  Other used their way, and they had success with "their way".  Those who didn't succeed didn't coach for long.

Putting myself in the above categories I found myself to be:

  1. Geometric - I watched areas of the field, not players.  I didn't scheme my opponent's gameplan, because I wanted him to play my game.  I didn't look at individual players, because I saw their abilities as a means to an end as a part of a whole.
  2. I approached the game in a passive philosophy.  Keep in mind that my "view" was aggressive (I wanted to dictate the game geometricaly by taking away my opponents space).  But my playcalling was based on not giving up big plays.
  3. I prefered to take away the pass.  I did this by fighting with the offensive coordinator for the fastest kids for the CB position.  (He got the fast kids with good hands for WR, and I got the rest; usually the fastest).  The smartest of the fast kids played at SAFs.  I felt I had a superior enough program of training and plays along my DL and with my LBs to hold down runs.  The DLs played a slant system which forced the OL to guess their blocks, and the LBs filled the gaps (instead of a true "man", "zone", or "contain" system).  This works in high school, but not beyond that.
  4. I was more of a "man coverage" guy.  Sure my LBs were used to "fill the gaps", but TEs were always covered (SS or SAM depending on speed of the TE), and CBs always played man.  SAFs almost always in zone.  My philosophy against the zone was that I had better have the people to play man well, or I wasn't doing something right in practice.
  5. I was a space oriented coach.  I took away gaps on the runs, and my game was built around the SAFs who broke from zone based on the areas of the field in jeapordy, not on where particular opponents were.

It may all seem a bit complicated, or may even sound a little too "ivory tower" to have any practical application.  I learned the above concepts from a seminar for coaches taught over a period of several days by several college coaches.  The idea was to know your own tendancies, so that you know your weaknesses and know what kind of systems best suit you.

So what does the future hold?  The current trend is the clash of the West Coast Offense and the Cover Two systems.  The WCO caused problems for a lot of defenses, but the C2 has slowed it.  But in a cruel twist, the C2 is not terribly effective against other offenses, and the WCO is most effective unless it runs up against a C2.  This goes back to what we discussed earlier, the idea of A beats B which beats C which in turn beats A.  Teams must thus develop a system to win in their divisions, then hope they are able to impose their system's application over the opponents (Coaching Axiom #1).

The three revolutions (or evolutions, depending on vantage) are thus:

  • Forward pass
  • Offensive line allowed to extend arms and hands
  • The West Coast Offense and the Cover Two counter
A technique, a rule change, then a system.  

But the future of the NFL (according to several seminars and coaches meetings over late nights at local pubs) is going to be none of the above.  The next step in the evolution of football may well be a position.  The complete extinction of the FB position, the elimination of emphasis on the WR position (eliminating several WRs), and the rise of the TE, used in three TE formations.

The fear this gives to defensive coordinators, and the elevation of the game to a higher standard (looking like the original game but with the modern pass systems) is awesome.

We'll talk about it next week in an article called "Magic Three".


In the meantime, I want for folks to send me ideas for future articles.  I will be addressing the questions submitted by "Make it Rain" in an article very soon, and I want to hear your ideas to.  

Also, take this time to ask any questions you may have about the article or anything else related to football.  No question is too simple.  If you don't even understand a "basic" rule (like scoring) I'm here for you.  If the question isn't an "Xs or Os" type question we have a lot of folks here that can get you an answer.

We'll move away from theory a little next week with the discussion of a specific system.  We'll look at the hypothetical "Magic Three" and look at formations and plays that proceed from it.

On the third week we will get down and dirty, addressing the kinds of things found in today's game.  In addition to "Make it Rain's" suggestions, I have articles ready to rock for the subjects we discussed yesterday.  These include:

  • What are the mechanics of the "Bootleg Plays" as employed by the Broncos?
  • What defensive system will Denver run in '08?
  • Would Batman be the answer at OLB, and is there any position on the team that could be played by Chris Hanson (of Dateline NBC's "To Catch a Predator")?
  • What is the "Zone Block" system?  How do different teams run it, and what are the strengths and weaknesses of the scheme?
  • What is the "staggered retirement" approach to building a team?
  • What is the theory of "Salary Cap Hell", and how does it destroy a team for years?  How is it cured?
  • A pre-season special - A look at the '08 schedule and the systems run by the Denver opponents.  (Not available until this summer)
  • Are the raiders "evil" because they choose to be evil, or because in a non-Euclidean universe they are destined to be evil because the Broncos are the force of "good" and must be opposed to prevent a vacuum matter collapse event? (See
Make it Rain's ideas:
  • Cover 3 (a formation), Tampa 2 (a system), cover 2 (a system), bump and run (a technique): What makes them successful? Why do they fail? What kind of players do you need to run each of them?  
  • I want to know more about gap assignments and different ways defensive linemen are instructed to play by their defensive coordinators.  
  • I would love a brief west coast offense 101 session so I can know more of the basics about the offense that I don't already know.  
Vote for what you want to see in week three, or offer a suggestion.  Take care!  (No homework!  Woo hoo!)


For week three, write about:

This poll is closed

  • 10%
    The bootleg
    (6 votes)
  • 13%
    Differences in the "cover" systems and formations
    (8 votes)
  • 5%
    Salary Cap Hell, and what is the staggered retirement system?
    (3 votes)
  • 5%
    Breaking down the West Coast Offense
    (3 votes)
  • 16%
    Gap assignments and an overview of the DL
    (10 votes)
  • 5%
    The raiders, evil by design or physics requires it?
    (3 votes)
  • 10%
    The Zoneblock
    (6 votes)
  • 3%
    Would Batman be a good fit at OLB?
    (2 votes)
  • 28%
    Denver's '08 system
    (17 votes)
  • 3%
    Bump and run vs. off coverage - player types, pros and cons
    (2 votes)
60 votes total Vote Now