Hong Kong Derby
Traditionally, the term "derby" is used strictly to refer to races restricted to three-year-olds, as the English and U.S. Triple Crown races all are. The most notable exceptions to this rule are the Hong Kong Derby and Singapore Derby, restricted to four-year-old Thoroughbreds, and the Canadian Pacing Derby, an annual harness race for "aged pacers" (Standardbreds) four years old and up.