A native of Philadelphia, Pennsylvania, Kimbrough graduated from Benjamin Franklin High School, where he starred on the school's baseball team, tossing a no-hitter in 1941.[1] A natural left-hander, he learned to throw right-handed as a child while recuperating from an injury.[1] He stated "I could throw them as hard left-handed as I could right-handed, with a better curveball left-handed."[1]
Independent accounts verifying that Kimbrough operated as a switch pitcher during his baseball career are lacking, but Kimbrough himself claimed that he earned a complete game victory in 1943 pitching from both sides. Other accounts verify his pitching win but not that he used both arms as a pitcher in that specific game.