In the 1960s, after training three consecutive Melbourne Cup winners, Adelaide trainer Bart Cummings earned the nickname 'The Cups King'. His success inspired him to expand his operations to Melbourne and Sydney, with every horse he entered in the Melbourne Cup drawing considerable attention.
Like his earlier champions, Think Big was bred in New Zealand and acquired by Cummings as a yearling. Sold to Mr. C.N. Tan—later known in Australia as Dato Tan Chin Nam—Tan would go on to own or co-own four Melbourne Cup winners under Cummings' guidance. A share of Think Big was also sold to Ric O’Sullivan from Brisbane.
Think Big's victory came at the expense of stablemate Leilani, a fan favourite, marking the third time Cummings' horses had finished first and second in the Cup. For jockey Harry White, it was the first of four Melbourne Cup triumphs.