MacTavish was born in 1934, in Johnsonburg, Pa. He moved to Chautauqua County and has spent 65 years here. He went to Southwestern Central School where he earned varsity letters in baseball, basketball and volleyball. MacTavish graduated in 1953 and the day after graduation he signed a professional baseball contract with then Brooklyn Dodgers. He was assigned to Hornell Dodgers of the PONY League (now the NY-P League) as a catcher. He played for Hornell in 1953 and Olean the next two seasons.
He became a certified basketball official in 1955 and joined the IAABO Board 39 that year and amazingly has been an official for 55 years. MacTavish was the president of Board 39 four years and during that time his board raised the most money of all boards for the Basketball Hall of Fame. The check was presented to the Basketball Hall of Fame and IAABO was honored between halves of a game at Yale University. Dr. Phil Fox, president of IAABO, and Lee Williams, executive director of the Basketball Hall of Fame, presented the award to Board 39.