I am much more of a defensive historian and front junkie than I am an offensive specialist, but all that said, if you’re like me and really want to know how the various defenses evolved, then you could do a lot worse than the first twelve pages of Homer Smith’s book. What Doctor Z did for the history of the 7 man line in professional football, Homer Smith does for both the 7 and 8 man line in both college and pro football in his first chapter.


A page from his phenomenal first chapter.

A page from his phenomenal first chapter.

The book is worth buying for the first chapter alone.

That said, as this is a playbook, the book is dominated by diagrams and concepts. It’s a very conceptual book. It’s heavy with categories and many lists of things to know and do. As an example, it has an appendix of pass techniques you can use to achieve separation. There are, by my count, 29 listed, in three broad categories.

He talks about things like simplifying reads, so that QBs have a binary decision tree instead of a five-six part list. That sounds to me like practical advice. He discusses kinds of pass defenses and how to recognize them. There are sections on time outs and time management, and when to go for 2 points. He talks about pass protection schemes, inside and outside runs, blocking schemes, and a lot of things I’ll never have the time to delve into.

But his excellent diagrams, often of defenses, are enough for someone like me to call this book a classic, and make me recall the various philosophy lectures I’ve heard, particularly on the Greek concept of arete. This, indeed, is an excellent book.


In Brian Burke’s recent roundup, he references a Fifth Down blog article on Rex Ryan’s philosophy of offense, one where running is heavily emphasized and the yardage? Not so much. He then says that as an offensive philosophy, it seems to be “ridiculous”, except in the metaphoric sense of a boxer, with a jab, using the run to keep an opponent off balance, so that he can lay out the “killing blow”.

I tend to think that Brian’s boxing metaphor is, at best, an incomplete picture. For one, he doesn’t see the jab as a knockout punch, but for Muhammad Ali, it was. Another point is the jab is fast, elusive, confusing. By contrast, the run is a slow play, and there is nothing particularly elusive or confusing about the run. Rex-like coaches often run when it is most expected.

The way Rex is using the run, in my opinion, is closely tied to the way Bill Parcells used to use the run, especially in the context of Super Bowl 25. This New York Times article, about Super Bowl 25, details Parcells’ view of the philosophy neatly.

Parcells' starting running backs averaged about 3.7 ypc throughout his NFL coaching career.

To quote Bill:

“I don’t know what the time of possession was,” the Giants’ coach would say after the Giants’ 20-19 victory over the Buffalo Bills in Super Bowl XXV. “But the whole plan was try to shorten the game for them.”

The purpose, of course, is time control, optimizing time of possession, and thus reducing the opportunity of the opposing offense to have big plays. It’s a classic reaction to an opponent’s big play offense, to their ability to create those terrific net yards per attempt stats [1].

Note also Rex is primarily a defensive coach. If the game changing, explosive component of a football team is the defense, doing everything to suppress the opponent’s offense only hands more tools to the defensive team. It forces the opponent’s offense to take risks to score at all. It makes them go down the field in the least amount of time possible. It takes the opponents out of their comfort zone, especially if they are used to large, early leads.

The value of time, though, is hard to quantify.  Successful time control is folded into stats like WPA, and thus is highly situation dependent. The value of such a strategy is very hard to determine with our current set of analytic tools. Total time of possession no more captures the real value of time any more than total running yards captures the real value of the running game in an offense.

Chris, from Smart Football, says that the classic tactic for a less talented team (a “David”) facing a more talented team (a “Goliath”) is to use plenty of risky plays, to throw the outcome into a high risk, high reward, high  variance regime. The opposite approach, to minimize the scoring chances of the opposition, is a bit neglected in Chris’s original analysis, because he assumed huge differences in talent. However, he explicitly includes it here, as a potential high variance “David” strategy.

It’s ironic to think of running as the strategy of an underdog, but that’s what it is in this instance. New England is the 500 pound gorilla in the AFC East, ranked #1 on offense 2 of the last 4 years, and that’s the team he has to beat. And think about it more, just a college analogy for now: what teams do you know, undersized and undermanned,  that use a ground game to keep them in the mix? It’s the military academies, teams like Army, Navy, and the Air Force, using ground based option football.

[1] The down side of a loose attitude towards first and second down yardage is that it places an emphasis on third down success rate, and thus execution in tough situations.

This is the  third of a series on drawing football diagrams, and this time we’ll be talking about drawing the defensive side of the ball. For now, we’re going to have the offense going “up” the image and the defense going “down” the image. It’s easy enough to invert. Draw the offense the way we show in Part 2, rotate the result by 180 degrees, and then add your defensive players. In the old days, the defense was indicated with triangles. Most football bloggers, however, like to use fonts with names on them for the defense. The problem with fonts is that fonts are often tied to an operating system, so using them well requires some familiarity with font families. A good introduction to font families is here. And to note, Helvetica is installed as part of Image Magick, so if you want a no nonsense solution that should just work, set your font to “Helvetica-Bold”.

Since we are using Image Magick to generate our graphics, we can add color at will to our diagrams, and so one convention we’re going to follow for now is to use shape and color to distinguish offense from defense. offenses will be in white, defenses in yellow. Other conventions we could use are:

  • Using different shapes for linemen, linebackers, and defensive backs.
  • Tilting the defensive symbol to indicate a slanted lineman.
  • Shading the offensive lineman to indicate a shaded orientation on the  part of the defensive player.

For now, we’re going to use this image as the basis for our defenses. We’ve spoken about the Desert Swarm, a kind of double eagle defense, here.

Arizona versus Washington, 1992. I formation versus Desert Swarm. Whip (flex tackle) on TE side of formation..

And these are our attempts to duplicate that photograph. Obviously one corner and the free safety position are a product of speculation.

Defense in yellow, using symbols. Slant lineman denoted by tilt of triangles.

This graphic is a text based representation of the defense.

Helvetica-Bold is the font used here.

The images as displayed above are about 3/4 their actual size, so double click on them to see a full sized image (unless you’re using Chrome, in which case you’ll get a huge image).

Font notes:

To list the fonts that Image Magick can use by name, use the command (Win32/64 cmd window or Unix shell):

convert -list font | more

fonts that are not listed here can be accessed by direct path to the font file itself. In Ubuntu/Linux, the Fontmatrix utility can be a big help in seeing which fonts are good and determining the font path.

In this article, the example code is going to be given in Perl, using the Image::Magick module.

Code samples:

Previous parts of this article: