Chris John, known in the dunk world as CJ Champion, is a 6'0" professional dunker. He goes up off two feet from a left-right plant, and his signature is the Eastbay.
He built his name on footage from The Dunk Camp, which for years has been where the sport's working dunkers gather to test verticals and film sessions together. That is where most people first saw him, and where the bulk of his catalogue comes from. His style leans on power rather than finesse, and he has generally been a contest dunker rather than a session-only one.
The defining chapter of his career so far is an Achilles tear, which is close to a worst-case injury for a jumper. The tendon is the primary lever in a two-foot takeoff, and recovery timelines run long enough that plenty of athletes never return to their previous numbers. He has rebuilt his vertical to 40 inches since, and is still working back toward where he was.
He also took part in episode 27 of the Dunk Talk podcast, a panel with Billy Doran of Dunkademics and Justin Barber of the World Dunk Association, on how dunking might grow into a more established sport. That conversation covered the practical problems the discipline still has, including inconsistent rim heights, thin prize money and the difficulty of building a career out of contests alone, all of which he has dealt with directly.