The Cowboys, historically a 4-3 defense team that won all five Super Bowls with that formation, will shift to a 3-4 base this season. New defensive coordinator Christian Parker emphasized flexibility, stating "being multiple is probably the most important thing" while acknowledging they'll use various defensive structures including 4-3 spacing and nickel packages.
This marks the Cowboys' first 3-4 base since 2012 under Rob Ryan. The team initially moved to 3-4 in 2005 under Bill Parcells and maintained it until 2013. After firing Matt Eberflus following the 2025 season where the defense allowed a franchise-worst 511 points, Parker brings experience from working with various defensive systems throughout his career.