Born on Long Island, New York, Hobbs became the youngest jockey ever to ride the winner of the English Grand National when successful on Battleship, a son of Man o' War, in 1938 just three months after his 17th birthday. Two weeks later, Hobbs won the Welsh Grand National on Timber Wolf. At the end of the 1937-38 season, during which he rode 35 winners, Hobbs made history by becoming the first jockey to win three Grand Nationals in one year, being successful in Long Island's Cedarhurst version.
A crashing fall in 1938 resulted in injuries including a broken spine. Although told he would never ride again, he returned to the saddle, but turned to training horses at age 25.
Hobbs retired from racing in 1985. He died in 2005, aged 84.