Just like Achilles with his heel, each racehorse in every race they compete possesses one major flaw. The top contenders for this year's Kentucky Derby, no matter how talented, are no exception.
These weaknesses might manifest in numberless ways: optimum distance, favored position during a race, surface preferences. Even something as seemingly innocuous as the environment in the paddock before a race can have a profound effect on a horse's performance.
Then there's the indisputable leveler: talent.
While designed to sift the wheat from the chaff, the main Kentucky Derby trials aren't always the best indication of how a horse is going to handle the cauldron of that first Saturday in May. Few races can replicate the unique demands of Churchill Downs on Derby day.
One thing is for sure, however: In the helter-skelter of America's most famous race, the chinks in the armor of each and every runner is going to be thoroughly examined.