 In key situations, a rush linebacker may be sent to cover the flat on the opposite side of the blitzing defensive back; this is called a "zone blitz".After becoming the predominant defensive alignment in the late 1970s-early 1980s, the 3–4 defense declined in popularity over the next two decades, but experienced a resurgence in the 2000s among both professional and college football teams.As of 2019, NFL teams that regularly incorporate the 3–4 defensive alignment scheme as a base include the Green Bay Packers, Los Angeles Rams, Pittsburgh Steelers, Baltimore Ravens, New York Giants, New York Jets, Carolina Panthers, Miami Dolphins, Tampa Bay Buccaneers, Denver Broncos, Tennessee Titans, Houston Texans, Chicago Bears, and the Arizona Cardinals.