Billy earned the nickname "Last-Race Cookie" following his riding of the winner in the last race 13 Saturdays in succession in Sydney.
He won six Sydney jockeys' premierships during a distinguished career riding in Australia and overseas.
Perhaps his most famous victory was defeating Phar Lap on Mollison in the 1929 Chelmsford Stakes.
Cook died in 1985 and was posthumously inducted in the Australian Racing Hall of Fame in 2002.
This Australian horse racing biographical article is a stub.