There are a variety of reasons to explain why a long list of outstanding horses were thwarted in their bid to become the 12th Triple Crown champion.

Some are predictable; others are surprising.

Premature moves, suicidal paces, injuries, medications, exhaustion and even a safety pin have all played a role in a drought that stood at 37 years until American Pharoah completed the sweep in 2015.

Every year when we gear up for the Breeders’ Cup, I always enjoy examining the pedigrees of the contenders. From the blue bloods destined for greatness from birth, to the discount stallions out of otherwise unremarkable mares, we see it all over those two days of racing.