Statistical boxing website BoxRec ranks Mandell as the 13th greatest lightweight boxer to have ever lived.

Despite this, his persistence in hanging around the wrestling and boxing training areas saw him gain permission to join in with the military personnel.

The camp boxing instructor at the time was Fred Dyer, "The Singing Boxer," who recalled in a 1926 interview how Mandell beat every soldier in the bantamweight class and was able to best men 10 lbs heavier than him.

[5][6] Trained by the legendary Jack Blackburn, Mandell was an outstanding, clever fighter who carried a solid punch, fast hands and superb defensive skills.

He successfully defended his crown against four contenders, including against hall of famers and future champions Tony Canzoneri and Jimmy McLarnin.