5 John Thomas Marshall — Age 28
Tom Marshall coached the Cincinnati Royals (now the Sacramento Kings) from 1958 to 1960, first as player-coach when he was 28, followed by assuming the full-fledged coach role. His 129-game coaching career yielded a 35-94 won-loss record. Prior to his coaching career, he played for the Royals when they were still based in Rochester from 1954 to 1955 and 1956 to 1957, before and after he served in the U.S. Army, as well as for the Detroit Pistons from 1957 and1958, before returning to the Royals in Cincinnati.
4 Vincent Joseph Boryla — Age 28
Vince Boryla or “Moose” started coaching the New York Knicks when he was 28 years old, after he played five seasons for them. He almost achieved a .500 victory percentage with an 80-85 career coaching record from 1955 to 1958. Boryla, a U.S. Navy, Army and Air Force veteran, saw success in basketball before and after his coaching career as basketball All-American at Notre Dame and the University of Denver. He won the gold with Team USA at the London 1948 Olympic Games as the first Notre Dame Fighting Irish Olympian. He was also general manager and chief scout of the Knicks and chief operating officer of the Denver Nuggets.
3 Arthur John Smiley — Age 27
“Jack” Smiley or “Smiles” was a 27-year-old player-coach for the Waterloo Hawks’ for only one season in the NBA in 1950, the year the Basketball Association of America changed its name to the National Basketball Association. He led the Hawks to an 11-16 record in 27 games, the same amount of losses they had under their other player-coach, Charley Shipp.
2 Walter Budko Jr. — Age 25
Walt Budko was 25 in 1950 when he coached the Baltimore Bullets (now the Washington Wizards), the team for which he also debuted as an NBA player. His short-lived stint as coach resulted in a 10-19 record. He played one more season in the league and recently passed away before his 88th birthday.
1 David Albert DeBusschere — Age 25
Dave DeBusschere or “Big D” for defense was just a fresh college graduate and already a multi-pro league athlete when he added youngest NBA coach in history to his resume at the ripe age of 24. He became player-coach of the Detroit Pistons in 1964 while playing one more season of minor-league baseball, after the Chicago White Sox kept him off the roster. After almost three seasons of coaching, he racked up a 79-143 record and never advanced to the post-season, as he did when he played exclusively. Once he stepped down as coach to play again in 1967, he felt more confident in his competence on the court.