Grantham's defense had some of the top talent in the country with playmakers at every position including linebackers Jarvis Jones and Alec Ogletree, defensive linemen John Jenkins and Kwame Geathers, cornerback Sanders Commings, and All-American free safety Bacarri Rambo. Jones was Grantham's star player and was once again a consensus All-American in 2012, finishing the regular season leading the nation in tackles for loss, and 3rd in sacks. Grantham is perhaps most famous for giving University of Florida kicker, Chas Henry, the "choke" sign as Henry lined up for the winning kick in the 2010 Florida-Georgia game. Grantham also was shown on TV in a confrontation with Vanderbilt Coach James Franklin after the 2011 Vandy game. He later acknowledged that his actions embarrassed the university and were "unfortunate". Neither coach apologized to the other. Under him Georgia defense finished No. 45 in the nation in the 2013–2014 season. It was the lowest the Bulldogs finished during Grantham's four-year tenure. Grantham was hired by Bobby Petrino to be his defensive coordinator at the University of Louisville. He was given a five-year guaranteed contract worth $1 million per year. Grantham was hired by Dan Mullen to be the defensive coordinator at Mississippi State University. He was given a multi year deal, with financial details not disclosed. Ironically, Grantham's predecessor at Mississippi State, Peter Sirmon, was hired to be defensive coordinator at the University of Louisville. On November 30, 2017, Mullen officially hired Grantham to be his defensive coordinator at Florida. Grantham had previously served as Mullen's defensive coordinator at Mississippi State during the 2017 season. In his first year at Florida, the Gators finished 28th in total defense nationally and 5th in the SEC. In February 2019, the Cincinnati Bengals zeroed in on Grantham to be their next defensive coordinator. Grantham ultimately rejected the Bengals' offer and decided to stay at Florida. Following his decision, Grantham received a contract extension and pay raise which made him one of the highest paid assistant coaches in college football.