He first began training horses as a side job while working for a livestock transportation company, and in 1967 attended the Tennessee Walking Horse National Celebration when Doug Wolaver won the World Grand Championship on Go Boy's Sundust.
[3] At the Celebration the following year, the pair won the World Grand Championship, beating 14 other horses and riders to do so.
[4][5] Gray competed in the Celebration consistently, and in 1975 won the Two-Year-Old World Championship with Powerful Delight.
[6] Gray won a second World Grand Championship in 1982 with the horse Pride's Secret Threat.
[9] In 2010, 26 years after his third win, Gray rode the chestnut stallion The Coach to a World Grand Championship.