Edward Patrick "Mickey" Walker was an American professional boxer who held both the world welterweight and world middleweight championships at different points in his career. Born in Elizabeth, New Jersey, he was also an avid golfer and would later be recognized as a renowned artist. Walker is widely considered one of the greatest fighters ever, with ESPN ranking him 17th on their list of the 50 Greatest Boxers of All-Time and boxing historian Bert Sugar placing him 11th in his Top 100 Fighters catalogue. Statistical website BoxRec rates Walker as the 6th best middleweight ever, while The Ring Magazine founder Nat Fleischer placed him at No. 4. The International Boxing Research Organization ranked Walker as the No. 4 middleweight and the No. 16 pound-for-pound fighter of all-time. Walker was inducted into the Ring magazine Hall of Fame in 1957 and the International Boxing Hall of Fame as a first-class member in 1990.

A knockout is a fight-ending, winning criterion in several full-contact combat sports, such as boxing, kickboxing, muay thai, mixed martial arts, karate, some forms of taekwondo and other sports involving striking, as well as fighting-based video games. A full knockout is considered any legal strike or combination thereof that renders an opponent unable to continue fighting.