In the late 2000s, the New England Patriots started to move away from the 3-4 base defensive looks that have helped them win three Super Bowls early in the decade. Instead, head coach Bill Belichick started to implement a 4-3 system. While it has since further evolved due to the rise of nickel and dime packages as the new base looks, the core ideas are still in place — and reflected in the players acquired to perform in the scheme.
This summer, however, the Patriots experimented with more classic 3-4 alignments (that would probably be morphed into a 3-3 in nickel looks with five defensive backs on the field).