Bly attended the University of North Carolina at Chapel Hill, where he played for the North Carolina Tar Heels football team. In his redshirt freshman season at UNC, he led the nation with 11 interceptions. He received all-American honors, and at the time was only one of five players in NCAA history to achieve this honor as a freshman. Bly was the only football player in UNC and Atlantic Coast Conference history to receive consensus first-team All-America honors twice in his college career. In his sophomore year, he was one of three finalists for the Bronko Nagurski National Defensive Player of the Year Award. Bly set the ACC record for career interceptions, which was later broken by Alphonso Smith of Wake Forest. He was elected to the College Football Hall of Fame in 2014.
Professional career
Pre-draft
St. Louis Rams
The St. Louis Rams selected Bly in the second round of the 1999 NFL Draft. Bly started his career in St. Louis, playing there for four years. While with the Rams, Bly won a Super Bowl ring for Super Bowl XXXIV. Two years later in Super Bowl XXXVI, the Rams lost to the New England Patriots, marking Bly's second Super Bowl with St. Louis.
First stint with Lions
In 2003, Bly left the St. Louis Rams and signed as a free agent with the Detroit Lions. He made the Pro Bowl in two of his seasons with the team. Bly was the 2003 recipient of the Detroit Lions/Detroit Sports Broadcasters Association/Pro Football Writers Association's Media-Friendly "Good Guy" Award. The Good Guy Award is given yearly to the Detroit Lions player who shows consideration to, and cooperation with the media at all times during the course of the season. On November 29, 2005, the day after Lions head coach Steve Mariucci was fired, Bly told the NFL Network that if their back-up quarterback, Jeff Garcia, had been healthy the entire season, the Lions would be in a better situation, and Mariucci would still be coaching the team. He has since apologized, albeit not to Joey Harrington, the Lions starting quarterback that season.
Denver Broncos
On March 1, 2007, Bly was traded by the Detroit Lions to the Denver Broncos for running back Tatum Bell, offensive tackle George Foster, and a 5th round draft pick. On March 28, 2007, the Denver Broncos and Bly agreed to a 5-year, $33 million contract. The contract included $18 million in bonus money and $16 million guaranteed. Bly finished the 2007 season as the Broncos leader in interceptions with five. The Broncos restructured Bly's contract on February 18, 2008 to free up salary cap space and keep Bly on the team. As of December 1, 2008, Bly had a total of 98 tackles and 7 interceptions with the Broncos. The Broncos released Bly on February 17, 2009.
San Francisco 49ers
On May 21, 2009, Bly signed a one-year, $845,000 contract with the San Francisco 49ers.
Second stint with Lions
On July 2, 2010, Bly re-signed with the Detroit Lions. Bly was released on September 4, 2010.
Bly and his wife Kristyn, have four sons: Trey, Jordan, AJ, and Emanuel and a daughter, Peyton. Bly also has an older sister Donna Mitchell, who is a high school teacher. Bly was voted into the Virginia Sports Hall of Fame in January 2017.
