Every stallion has a “tell,” says Bridgette Jablonsky, and, in this moment, in a dimly lit barn at Hanover Shoe Farms in Hanover, Pa., Somebeachsomewhere, the legendary Canadian harness racing champion and international Hall of Fame horse, is telling Jablonsky he is ready to perform. Somebeachsomewhere’s readiness is never a certainty. He is a finicky and, at times, apathetic lover. To hasten his readiness Chiptease, a mare in heat, is in the barn, standing idly by as her would-be mate nips at her hindquarters, throws back his head, inhales deeply and, after 10 minutes, starts dancing about on his hooves....