In terms of last-race drama, we couldn’t have scripted the Exacta Extravaganza much better. In as contentious a race as you’re ever going to see, Dylan Donnelly, 30, of Alta Loma, Calif., saw two of his three exacta box horses—Hallie’s Hero (9-1) and Abbaa (also 9-1)—prevail in a five-horse blanket finish in the final race […]