Whicker: A free-flowing day at the races for trainer Simon Callaghan

ARCADIA — The real River Boyne flows 70 miles through farm country, and into the Irish Sea.
The horse named River Boyne flows unimpeded around Santa Anita Park, and then comes ashore in mighty fashion at the finish line.
At least that was his history.
River Boyne was 6-0 at Santa Anita until Saturday in the Thunder Road Stakes, when jockey Flavian Prat ran up against a dam. Well, a colt, actually, but Prat got boxed in and watched True Valour, another Irish representative, swoop in for vic