Seattle Cover 3 defense
The Seattle Cover 3 is a Cover 3 defense crafted by Seattle Seahawks coaches Pete Carroll and Dan Quinn that lead the NFL in total defense in 2013 and 2014, helping the team win two NFC Championships and Super Bowl XLVIII. The defense used a 4-3 base formation while incorporating 3–4 defensive principles using a hybrid defensive end-linebacker position known as the Leo. It featured a strong secondary nicknamed the Legion of Boom.