The Victor's Qualifications (勝利者への資格, Shōrisha e no Shikaku) is the fourteenth volume of Steel Ball Run and the ninety-fourth volume of the JoJo's Bizarre Adventure manga. It covers most of the "Wrecking Ball" story arc.
I often see the phrase "horse and man as one" in racing magazines or in historical novels, and it supposedly means that the rider can synchronize his or her movements with their horse, so that they're almost one entity. When I draw Gyro and the others on their horses, I feel like I understand a bit of what that phrase means, though I don't ride horses myself. I can't tell you specifically which ones they are, but when I get a racing panel to look just right, the figures seem to fit well with one another. Humans and horses must be biologically suited for one another (whatever that means).