Moriarty played four reserves games at the end of the 1915 season, before the league went into recess for three years due to World War I.
Moriarty was selected in the South Australian team in interstate matches in 1919, and represented the state regularly throughout his career.
[3] Moriarty's size (178 cm, 76 kg) was small compared with most of the other great centre half-backs in the history of the game.
As a defender, he tightly marked his direct opponent,[2] had a very high leap with which he could spoil the ball, and was credited with a strong ability to read and anticipate the play; in a self-assessment, Moriarty credited his ability to read the play as the most important contributor to his success as a player.
He has been inducted into four halls of fame: He was named at centre half-back in the South Adelaide Football Club's Official Greatest Team.