The Cowboys have historically used a 4‑3 defense, winning all five Super Bowls with that scheme. The switch to a 3‑4 base marks the first time since 2012 under Rob Ryan.
Defensive coordinator Christian Parker, who has worked under Vic Fangio, Vance Joseph, Mike Pettine and Mike Elko, said the new scheme will be multiple and built around the team's strong defensive line featuring Quinnen Williams, Kenny Clark and Osa Odighizuwa.