Rumors have been swirling that the Chicago Bears are pondering a switch on defense to a 3-4 from the 4-3 base they used last season. The recent additions to the defensive coaching staff each have experience in both 4-3 and 3-4 schemes, and these additions have only added to the commotion. Before taking a stance on which way the Bears should go, fans should have a basic understanding of everything that goes into a scheme change.
A switch to a 3-4 defense would demand general manager Phil Emery to focus his efforts on acquiring the right players for the scheme in free agency and the 2014 NFL Draft. Simply put, the Bears would need to change their defensive line personnel by adding a bigger nose tackle and bigger defensive ends. Moving to the next level of the defense, Emery would need to make a significant move or two to acquire linebackers to fit the four-linebacker scheme. Emery would also need to snag another capable safety to better fit the scheme.
Schematically, throwing out an entire playbook that had just been installed and taught less than a year ago is not ideal. Some terminology with blitz packages and coverage sets could be carried over, but the defensive line terminology would require a complete overhaul. The proposition of defensive coordinator Mel Tucker performing a ground-up remodel of his 4-3 scheme would lead to another season of defensive woes.
The logistics of installing a new defensive playbook for the second consecutive season and the challenge of adding so many new scheme-fitting players with limited cap space is severely unrealistic. The Bears will be much better off sticking with the current 4-3 scheme and acquiring players to fit the defense they installed a year ago.