Riddick was a member of American 4 × 100 m relay team, which won the 1977 IAAF World Cup with a new world record of 38.03 s (with Cliff Wiley, Bill Collins and Steve Williams). He was also a member of American 4 × 100 m relay team, which won the 1979 Pan American Games(with Mike Roberson, Harvey Glance and Cliff Wiley) and placed second in 1979 IAAF World Cup (with Mike Roberson, Harvey Glance and Mel Lattany).