The Cowboys have historically run a 4‑3 defense, winning all five of their Super Bowls with that scheme. They first switched to a 3‑4 in 2005 and used it until 2013, but have since returned to 4‑3 and hybrid fronts.
Christian Parker, hired as defensive coordinator, announced the shift to a 3‑4 base for the 2026 season. He said the new structure will allow the defense to be more multiple and adaptable, with 4‑3 spacing and nickel variations as needed.