Marshall Diebold was born in Madison, Wisconsin, in 1903, and graduated from the University of Wisconsin in 1925. He learned his basketball under Dr. Walter Meanwell, and in 1923-24 and 1924-25 he was selected as a guard on the All-Conference and All-Western teams.
Coming to Carleton in 1930 as head coach of basketball and baseball, Diebold was named athletic director in 1931. In twelve seasons as basketball coach, he piloted teams to five Midwest Conference championships, winning 63 and losing 28, for a .692 record in the MWC. His overall record of 126 wins and 75 losses included victories over Big Ten opponents Iowa (twice), Minnesota (twice), Wisconsin and Chicago. His teams also triumphed over Nebraska, Drake, Oklahoma A&M, Kansas State and DePaul.
The years from 1930 through 1933 saw the Carl cagers dubbed the “Victory Five” by Twin Cities sportswriters. Those three teams, spearheaded by the likes of Dick Arney, “Boots” Taylor, Matt Thoeny, Eric Storm, Chet Raasch, Gus Young and “Tubby” Nordly, won 43 games and lost but five, all to Big Ten teams. Diebold-coached teams were undefeated in Midwest Conference play for four consecutive years, and went five years without a loss in Sayles-Hill Gymnasium.
Coach Diebold left Carleton in 1942.