Tampa Two defense a product of age of specialization

	Though smaller than the model linebacker, Ernie Sims' speed is what the Lions needed most in their new Tampa Two defense. Jonathan Daniel/Getty Images
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Back on my summer training camp tour, I found myself interviewing Detroit Lions' rookie linebacker Ernie Sims on a warm Thursday afternoon. We were in the Lions' cavernous indoor training facility in suburban Dearborn, Mich., walking the length of the spongy FieldTurf surface. I remember that Sims, just a few months out of Florida State, was excited because his family had flown up north to see him play an exhibition game against Denver the next night at Ford Field.

I also remember how small Sims looked. He's listed in the Lions' media guide as 5-foot-11, 221 pounds, and I don't question the accuracy of those numbers. (Well, maybe I question the accuracy of the 5-11, but everybody lies about height, in and out of professional sports. I've been 5-11 3/4 for a long time, but my program height has drifted back and forth between 6-0 and 6-1. I have interviewed football players who claim 6-4 and I can almost look them in the eyeballs).

Sims probably weighed a little less than 220 pounds at the time, because we're talking about the end of Lions' coach Rod Marinelli's first training camp, and it was brutal. But even at every inch of 5-11 and every pound of 221, Sims is not a huge man. At a quick glance, he looks like a cornerback. Except that I had just finished talking to Dre' Bly, who is a cornerback and he's only 5-9, albeit a chiseled 188 pounds. Still, Sims, though maybe not an imposing physical presence, is the perfect size for what Marinelli and the Lions need in implementing their defensive scheme, the Cover Two.

Specialization is one of the central elements of the now ubiquitous Cover Two zone defense scheme I wrote about for this week's issue of Sports Illustrated. Increasingly, the approach has become known as the "Tampa Two," because it came to serious prominence with the Bucs under head coach Tony Dungy and defensive coordinator Monte Kiffin in the late 90s and early 2000s.

The people who run Tampa Two -- and there are a lot of them in the NFL these days playing Tampa Two for at least part of every game -- are looking to draft a very specific player at each position. Never mind the old "best athlete available'' mantra. In this scheme, that's out the window.

Let backtrack and quickly summarize the scheme. I'll make it quick; if you want the entire 411 I recommend reading the story in SI or here on si.com.

Tampa Two is a scheme that employs a Cover Two coverage, with two deep safeties splitting the field. That's been around forever. What makes Tampa Two different is that the cornerbacks play rolled up tight and jam receivers, while the outside linebackers fill drop zones and the middle linebacker roams from the line of scrimmage to more than 30 yards down the field.