10 best coaches who haven’t won NBA Coach of the Year

6. Larry Costello (1969-79)

Costello had a successful decade coaching in the league, mostly leading the Milwaukee Bucks in the 70s. During his coaching career, Costello won 430 games with a .589% regular season winning percentage. He also won 37 playoff games and finished his career with a .617% playoff winning percentage and a 1971 NBA Finals victory with the Bucks.