By Breeders; Cup Press Staff — The schedule of this weekend’s Challenge Series races appears below:
| DATE | TRACK | RACE | GRADE | DISTANCE | CONDITIONS | DIVISION |
| 10/8/21 | Kee | Darley Alcibiades | I | 1 1/16 Miles | 2 YO F | Juvenile Fillies |
| 10/8/21 | Kee | Stoll Keenon Ogden Phoenix | II | 6 Furlongs | 3 YO & UP | Sprint |
| 10/9/21 | Bel | The Vosburgh | II | 6 Furlongs | 3 YO & UP | Sprint |
| 10/9/21 | Kee | Claiborne Breeders’ Futurity | I | 1 1/16 Miles | 2 YO | TVG Juvenile |
| 10/9/21 | Kee | First Lady Presented by UK HealthCare | I | 1 Mile (T) | 3 YO & UP F&M | Maker’s Mark Filly & Mare Turf |
| 10/9/21 | Kee | Keeneland Turf Mile | I | 1 Mile (T) | 3 YO & UP | Mile |
| 10/9/21 | Kee | Thoroughbred Club of America | II | 6 Furlongs | 3 YO & UP F&M | Filly & Mare Sprint |
| 10/10/21 | Bel | The Futurity | III | 6 Furlongs (T) | 2 YO C&G | Juvenile Turf Sprint |
| 10/10/21 | Kee | Castle and Key Bourbon Stakes | II | 1 1/16 Miles (T) | 2 YO | Juvenile Turf |
| 10/10/21 | Kee | Indian Summer Stakes | 5 1/2 Furlongs (T) | 2 YO | Juvenile Turf Sprint | |
| 10/10/21 | Kee | Juddmonte Spinster | I | 1 1/8 Miles | 3 YO & UP F&M | Longines Distaff |
