In 2013 John Harbaugh hired his old Eagles friend, Juan Castillo to be the offensive line coach. Everyone freaked out that we hired a defensive coordinator to coach the offensive line; though it slipped their minds that’s what he has done his entire career. Andy Reid made him his defensive coordinator in 2012 for some reason nobody really understands. Castillo brought a much more intense focus on the zone blocking scheme.
The offensive line struggled in 2013 and many Ravens fans blamed Castillo and his “new” blocking scheme. Then Gary Kubiak (who is practically a zone blocking professor) came to town in 2014.