The Thousand Guineas is one of the feature races on Caulfield Guineas Day.

Run over the same distance and for the same age as the Caulfield Guineas, the Thousand Guineas is the female equivalent of the race, as it is only open to fillies. The Caulfield Guineas meanwhile is predominantly a race for the boys.

First contested in 1946, the Thousand Guineas has always been run over the distance of a mile. It was in 1979 that the race was given Group One listing. Now, it sits alongside three other Group Ones at the Caulfield Guineas meet, which is regarded by racing purists as one of the best days on the Australian racing calendar.

Just how the Thousand Guineas is regarded as the female version of the Caulfield Guineas, it can also be considered as the Melbourne version of Sydney's Flight Stakes. Both the Thousand Guineas and Flight Stakes are mile races for three-year-old fillies, and both can be used as a stepping stone onto the VRC Oaks, which is contested over 2,500 metres. 

But there's no doubt that the Thousand Guineas is a ripping race in its own right. Some of the country's best fillies assemble for the race, that more often than not throws up a thrilling finish.

Because most of the fillies won't have much form over a distance longer than 1,400 metres, the Thousand Guineas can be a difficult race to line up for punters.

This difficulty is reflected in the starting prices of recent winners, with three of the past six winners starting in double-figure odds.