Bass was World Featherweight Champion in 1927 and 1928 and
World Junior Lightweight Champion, in 1929–1931.

The 5'11/2" Bass, whose career weight ranged from 120 to 135 pounds, had 63 knockouts in 172 victories en route to winning two World titles within 25 months. He won the World Featherweight crown in September 1927 and lost it five months later to Tony Canzoneri. Moving up a class, he captured the World Junior Welterweight Championship in December 1929 and held the crown for 19 months.

In 1920, at age 16, Bass won the U.S. Middle States Flyweight Championship. He turned pro as a bantamweight in 1922 and did not retire until 1940. His professional record: 227 bouts—172 wins (63 by KO), 38 losses, 10 draws, 1 no decision, 2 no-contests.