Champion Fillies Who Decided Not To Run Any More

On another thread ... Oracle mentioned Storm Flag Flying, Meadow Star, Lady's Secret, and Winning Colors ... as champion fillies who decided that they weren't going to be race horses any more.

I knew of several more ... and did a bit of research ... coming up with this list of champion fillies who one day decided to stop racing ... and performed 20 lengths or more below their best form ... without having been injured ...

Now What, Bridal Flower, Busher, But Why Not, Level Best, Miss Request, Stefanita, War Plumage, Aunt Jinny, Grecian Queen, High Voltage, Parlo, Quill, Rose Jet, Sweet Patootie, Berlo, Furl Sail, Lady Pitt, Regal Gleam, Royal Native, It's In The Air, Sensational, Smart Angle, Tempest Queen, Open Mind, Sacahuista, Countess Diana.

Is there a horse psychiatrist out there ... who can explain this?