Found this to be an interesting read and would love your general thoughts. The author effectively argues that most modern defenses are no longer best explained through 43 or 34 concepts, but as two base nickel concepts: 2-4-5 versus 3-3-5. As Boyd discusses, each takes on some of the principles from various over/under versions of the 34 or 43, but have changed as a base defense enough that it becomes easier to understand college defenses as having evolved beyond 43 and 34 base philosophies.
