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:

My recent explorations with the program Image Magick has left me thinking: since Image Magick is intended to be used in web sites, where people mass produce images (Image Magick can, for example, take a whole folder full of photos and generate thumbnail images), could I use Image Magick to create the outlines of football fields, complete with yardage lines and hash marks? And the answer so far is yes. Dimensions for football fields can be found here, on SportsKnowHow.com. The question then is translating those measurements into the dimensions of a regular screen size, such as 640 by 480 or 800 by 600. Please note that the American field is always 160 feet wide, so images whose width is divisible by 160 are desirable.

As an example of what can be done, I’ll show this image of a 46 defense versus a pro style offense on a pro style football field. Note that the image is displayed half of full size. Double click on the image to display full size.

46 defense from a 34 base, versus a pro style offense, pro hash marks.

All the diagram components have been placed with a set of three programs. The first generates three fields, one of pro, one of college and one of high school dimensions. The second places the offense on the field. The third handles the annotations of the defense.

A piece of the football field creation batch file.

A html-ised version of the batch file above is available here. Just cut and paste into a batch file on your local computer and correct variables as directed in the header.

So far I’m not using anything sophisticated to make these images, just batch files. I’m using batch because once I clean these up, I want to make them available to the Deuces and Coach Hoovers of this world for free. And to the high school coach who only has a Windows laptop or desktop, a batch file is the appropriate tool for automating something like this.

Remaining issues: are the hash marks given in the links above at the beginning of the distance from the sideline, at the middle of the distance from the sideline, or at the end of the distance from the sideline? I know it’s at most a 2 foot error, but I’d like to know. Likewise, does anyone know the best font for the numbers one might write on a football field? They’re 6 feet fall, 4 feet wide, and placed so the tip of the number is 9 feet deep into the field. Numbers aren’t essential at this point, just an aesthetic trick.

Update: It’s clear that in pro ball, there are vertical as well as horizontal hashmarks, and the horizontal ones are outside the vertical ones.

Amazon.com, if you guys don’t know, is a  terrific source of penny books, books that third parties sell through Amazon for a penny. I’ve picked up a slew of books that way, and I’m reading quite a few of them. Of them, the most promising is “Education of a Coach” by David Halberstam, but I’m not going to talk about it until I finish some film study of the 1990 Super Bowl. David Halberstam has said some things about that game that absolutely deserve video study, so I’m in the middle of doing that. In  the meantime, I’ll mention a book I picked up for sentimental reasons, my father’s only football book when I was young, the book “Championship Football”, by Dana X. Bible.

Originally copyrighted in 1947, and a fifth printing from 1949, the book is old. The book is musty, and it’s a library copy from a junior high near Texarkana Texas. For all I know, this book was held by H Ross Perot some time in the past.

My first impression was how relevant the material was. Not the bits on strategy, but other things, like plays, like tips on playing, tips on blocking technique, tips on tackling a quarterback higher, so that you pin his arms to his body. Photographs, such as Bobby Lane showing people how to pass the ball, and players in 2, 3, and 4 point stances, are useful. Someone needs to resurrect this book, at least in PDF form, if nothing else.

The late 40s were a period when the T formation was coming into common use, but the older formations, such as the single and double wing, long and short punt formations, were still around. Dana talks knowledgeably about spinning backs, or spinners.

Dr Z: Vick as back 4, Duckett as 3, Dunn as 1, Koslowski as 2.

Spinners? You are a Dr Z fan, aren’t you? Can’t you remember Dr Z, Paul Zimmerman, trying to convince Dan Reeves to use Michael Vick as a single wing tailback, and growing sentimental about spinners?

In my dream, I lined up Vick at the run-pass tailback spot. T.J. Duckett was my spinning fullback. Warrick Dunn was the wingback, and Brian Kozlowski, normally the second tight end, was the blocking back. I just couldn’t shake the vision. Finally I called Dan Reeves, who was the Falcons’ coach at the time. Of all the loony calls he’s ever gotten, this must have ranked right up there. Anyway, I laid it all out for him, ending with Duckett as the old Michigan-style spinning fullback.

“What’s a spinning fullback?” Reeves said, and I realized that I was either real old or just dopier than usual. The idea never got any further, but I still think something like that would light up the sky.

Well, Dana has a whole page (or more) on spinners, and not just spinners, he offers a variety of formations on those pages.

Zone defenses, 1940s style. The 5-4 is what we'd call a 34 today.

Curious about the origins of scouting? Wonder how it was done before Steve Belichick came out with his scouting book? I found it interesting to compare pages between the older and the newer book. Seem familiar?

Scouting tips from Steve's book

Scouting tips from Dana's book.

Of course, strategy in those days was incredibly conservative, as offenses were not really well developed in  those days.This is a strategy chart from Dana’s book.

That chart did more to throw me for a loop than anything else, though when teams would quick kick here and there, I was at least ready for the tactic.

Upshot? Terrific book. It probably needs to be preserved in a PDF version, one that won’t age over time. These library copies won’t be around forever.

Update: Google Books has a scan of this book.