In
1961, he was signed as an
undrafted free agent by the
Dallas Cowboys, but because head coach
Tom Landry felt he lacked size for the physical play that was needed in NFL at the time, Chief talent scout
Gil Brandt called the AFL's
Dallas Texans head coach
Hank Stram and suggested he give Grayson a look. Grayson made the team and played four years with the
Dallas Texans/
Kansas City Chiefs. In
1961, he set the franchise and AFL record for the longest interception return with a 99-yarder against the
New York Titans. In
1961, he also led the league in kickoff returns. In
1962 and
1963, he finished second in the league in kickoff returns. In
1965, he was traded to the
Oakland Raiders in exchange for
cornerback Fred Williamson. Grayson held the AFL record for longest
interception return for a
touchdown, 99 yards, against the
New York Titans in
1961. He had an interception off
George Blanda in the Texans'
1962 double-overtime championship game victory over the defending AFL champion
Houston Oilers. Grayson was an
AFL All-Star six times, with the Texans/Chiefs in
1962,
1963 and
1964, and with the Raiders in
1965,
1966 and
1969. In
1967, he was moved from right
cornerback to
safety. He made a 48-yard return with the opening
kickoff against the Oilers in the
1967 AFL Championship Game, helping his team win the game and reach
Super Bowl II. In
1968, he led the AFL with 10 interceptions. His 29 interceptions rank seventh all-time in Raiders history. Grayson is the all-time AFL leader in interceptions with 47, for a 20-yard return average and 5 touchdowns, and he averaged 25.4 yards on 110 kickoff returns. He is a member of the
AFL All-Time Team. Despite his accomplishments, Grayson has yet to be inducted into the
Pro Football Hall of Fame. He remains the only first-team defensive back from the AFL All-Time Team to not be selected. In 2017, the
Professional Football Researchers Association named Grayson to the PFRA Hall of Very Good Class of 2017. ==Personal life==