Gallop Racer is an open-ended game. You buy horses to train, race, and breed. Most of the Gallop Racer franchise revolves around this theme. Gallop Racer 2004 breaks this theme and puts more emphasis on the jockey, than on the horses.
Source: Wikipedia, "Gallop Racer 2004", available under the CC-BY-SA License.
Like the previous installments in this series, the player uses stats to choose horses and jockeys. The races themselves have some choices, mostly start and finish actions, but they are mostly controlled by the stats matching particular race tracks.