American Pharoah

When Pioneer of the Nile retired to stud, his fee was no higher than $20,000 (and was soon to fall to $15,000). Even so, Churchill Downs on the first Saturday in May seemed likely to become embedded in the DNA of his best progeny. Pioneer of the Nile had himself made it to the GI Kentucky Derby, finishing second to Mine That Bird in 2009, and so had his sire Empire Maker, runner-up as the clear favorite in 2003. His grandsire Unbridled had fared better, accounting for Summer Squall and Pleasant Tap in 1990.