LeBeau's system commonly calls upon linemen to be mobile enough to drop back into zone coverage in place of blitzing linebackers. Elements of the 3–4 zone blitz defense have been incorporated over time into the modern Phillips 3–4.
LeBeau's system frequently relies on linemen to be agile enough to fall back into zone coverage in place of sending blitzing linebackers. Components of the 3–4 zone blitz defense have been integrated over time into the contemporary Phillips 3–4.