Breeders’ Cup roundup: Immersive impressive in Juvenile Fillies

DEL MAR — Sometimes the Breeders’ Cup anoints greatness, and just as often horse racing’s championship event adds to it.

Although two-time national champion trainer Brad Cox has developed some of America’s top fillies and mares in the past decade, none was as far along in the fall of her 2-year-old season as Cox’s new star Immersive is.

“For 2-year-old fillies, she’s the best we’ve had,” Cox said, which is saying something, since the 44-year-old Kentuckian’s prominent females include Monomoy Girl...