Born in
Chicago, Illinois, Nagle was educated at
Shorewood High School and at Marquette, where he lettered in both the 1938–39 and 1939–40 seasons, as a reserve guard on the team. Following graduation, Nagle served in the
United States Army Air Corps (USAAC) from 1940 to 1944. After leaving the military, Nagle was named an assistant coach at Marquette under his former coach,
Bill Chandler, and later under
Fred "Tex" Winter. Nagle was named head coach of the Warriors in 1953 after Winter left to return to
Kansas State as that school's head coach. Nagle was also instrumental in the renaming of the team from the Marquette Hilltoppers to the Warriors. The first Marquette men's basketball team to earn a trip to the
NCAA Tournament was the 1954–55 team, in Nagle's second year as head coach. The team had its first ever 20-win season, compiling a 24–3 record. The team reached as high as No. 4 in the AP Poll before finishing the season ranked No. 8. Marquette beat Miami (Ohio) University in the first round of the tournament 90–79 and then beat No. 2 Kentucky, 79–71 in the second round. Marquette then lost to No. 5 Iowa in the
Elite Eight, 86–81. Nagle's record over five seasons at Marquette was 69–55 (55.6%). In 1958, Nagle left the college coaching ranks and took a position at
Whitefish Bay High School in suburban
Milwaukee,
Wisconsin, and coaching the boys' varsity basketball team from 1962 to 1972 and the girls' varsity team from 1973 to 1989. Both his boys and girls teams made appearances in the Wisconsin state high school basketball tournament. Nagle is the only coach in American basketball history to coach teams in the NCAA tournament and both a boys and girls state high school tournament. In the 1980s, Nagle was a scout for the
Cleveland Cavaliers and later the
Dallas Mavericks. He was a charter member of the Wisconsin High School Basketball Association Hall of Fame and was voted Wisconsin High School Coach of the Year 10 times. Nagle also served as commissioner of the
Continental Basketball Association. Nagle was one of the early proponents of summer basketball camps to teach skills, beginning day camps in the mid-1960s. In 1986, he authored a popular coaching book titled
Power Pattern Offenses for Winning Basketball. He died in 1990 in
Shorewood, Wisconsin. Nagle's eldest son, Chuck, was a three-year starter at the
University of Wisconsin–Madison (67/68–69/70). == Head coaching record ==