Cobb was born on May 7, 1950, in
Bridge City, Texas, the son of Norma Grace (
née Alexander) and Williard Glynn Cobb, a factory foreman. His mother was of Scottish ancestry. He was raised in
Abilene, Texas, and attended
Abilene High School, where he played on the football team. Cobb later studied at
Abilene Christian University, but dropped out at the age of 19, and began
karate training. He lived in the
dojo, cleaning the mats to earn his keep. After earning his
black belt, he craved full-contact competition, thus took up
kickboxing, fighting in an era when only
full contact rules were used in the United States. He won his first five kickboxing matches, going 5–0 with all
knockouts before losing to John Jackson by decision. He
TKO'd El Paso Golden Gloves Heavyweight Champion and karate black belt, David Ochoa, in the first-ever full contact martial arts event in
El Paso, Texas, in 1975. The promoters were Robert Nava and boxing trainer Tom McKay under the guidance of boxing guru and matchmaker, Paul Clinite. Clinite signed Randall to a professional-boxing contract a few weeks later. He also signed Ochoa, who had fought amateur under the guidance of McKay as his trainer. Clinite provided films of heavyweight boxers to study, to get the huge Cobb a good style. After a few days, it was decided that Randall should work at learning the "
Joe Louis shuffle". Randall, Paul, and Tom spent a few months at El Paso's San Juan Boxing Gym just doing the simple basics. A few months later, Clinite made arrangements for Randall to be sent to
Joe Frazier's gym in
Philadelphia. ==Boxing career==