ARCADIA, Calif. — Trainer Dale Romans calls Shackleford his best shot for a win in the Breeders’ Cup this weekend at Santa Anita.

‘‘He’s definitely our most live horse,’’ Romans said of the winner of the Metropolitan Mile in May and the 2011 Preakness. ‘‘All of our horses are coming into the races doing well, and all have chances. I think he’s the closest to one that should win.’’