Even with his success, Dunn’s career can also be a warning about the 3-3-5. He’s held down jobs with good schools, but he never was able to break out beyond schools like Memphis, Mississippi State, and Ole Miss. While at their best, his defenses were suffocating and hard to plan for; when the talent dropped off, the aggressiveness once viewed as a virtue seemed to bleed over into a lack of discipline and a penchant for giving up big plays. Since then, he has coached at Ridgeway High School, New Mexico State, and now Division III McMurry. In football, pragmatism rules, and inflexibility — even if it’s with a great idea — leads to the rest of the landscape passing you by.
His legacy is nevertheless secure. Dunn is essentially the father of the 3-3-5, and the coaches that now use it, even if only in certain situations, are his descendants. The original “30 stack” 3-3-5 is no longer the defense of the future. As with most schemes, age has exposed many of its weaknesses, and many of its leading practitioners, like Charlie Strong, have moved on to other fronts and use it as only a subpackage. But in the age of pass-first and spread offenses, the principles underlying it — movement, disguise, aggressiveness, and an extreme focus on speed — are more important than ever.