 The Carolina Panthers ran a 3–4 base defense in the 2019 season for the first time since the late 1990s.The Arizona Cardinals ran the 3–4 under coordinators Todd Bowles and James Bettcher from 2013-17, but switched to the 4–3 in 2018 under head coach Steve Wilks, who ran the 4–3 as defensive coordinator for Ron Rivera with the Carolina Panthers.In 2019, the Cardinals returned to the 3–4 under new defensive coordinator Vance Joseph, the former Broncos head coach hired by new Arizona coach Kliff Kingsbury.