Bailey, at 184 pounds, ran a 4.28 second 40-yard dash, 3.79 second 20-yard shuttle and had a vertical jump of 37 inches at the 1999 NFL Combine
Bailey's reputation as a shutdown corner was established at the professional level. He was a large presence on a defense that had its ups and downs. He benefitted from time spent with iconic cornerbacks Deion Sanders and Darrell Green; both are considered among the best of all time. In tandem with Fred Smoot and the aforementioned greats, Champ helped establish a near legendary era of man-to-man coverage for the 'Skins.
Prior to the 2004 season, he was traded to the Broncos along with a second-round draft pick (who ended up being Tatum Bell) for Clinton Portis. Following the trade, he signed a seven-year contract worth $63 million. Bailey has been named to seven consecutive Pro Bowls and 3 All-Pro teams.
On January 14, 2006 in a divisional playoff game between the New England Patriots and the Denver Broncos, Bailey broke the record for the longest non-scoring play in NFL history. With the Patriots poised to score, Bailey intercepted a pass from Tom Brady in the end zone and returned it 100 yards to the 1 yard line, and fumbled the ball out of bounds, after being hit by Patriots tight end Benjamin Watson, who also went to Georgia. The Patriots challenged, in the hope that the ball was fumbled through the end zone, but there was not enough evidence to overturn the call, and the play stood. The Broncos scored a touchdown on the next play. The play was considered the most crucial of the contest, which the Broncos would go on to win, hence ending the Patriots' quest for a historic third straight Super Bowl title.
Against the defending NFC champion Seattle Seahawks on December 3, 2006, The Seahawks did not test Bailey once in the first half. The first time Matt Hasselbeck threw in Bailey’s direction, the cornerback intercepted a deep throw intended for Darrell Jackson.
Hasselbeck was not surprised saying in an interview following the game, "I've thrown him interceptions in my career, who hasn't? He's a great corner, a great cover guy and just a very, very talented guy."
In the 2006 NFL season, Champ had 10 interceptions through the season (tied for the NFL lead with Asante Samuel). Bailey also did not give up a touchdown during the season. Bailey has been noted on many occasions by sources such as NFL.com and ESPN as the best cornerback in the league and a future hall of famer.