It’s fitting that Aidan O’Brien’s first Breeders’ Cup runner was Second Empire. Although he was only sixth at odds of 21-1 in the 1998 Mile (G1), the colt’s name can be reinterpreted with the benefit of hindsight. Instead of an allusion to 19th-century French history, “Second Empire” could be taken as the reign of this second O’Brien at Ballydoyle, building upon the first established by the legendary Vincent O’Brien.

Aidan isn’t related to Vincent (unless you posit an ancestral connection lost in the mists of time), but the younger O’Brien is his true successor in developing equine talent. If he’s benefited from having a series of bluebloods to train, merely having the raw materials isn’t enough. Aidan O’Brien has the natural, intuitive horsemanship to draw out that latent potential, as his scores of European classic winners prove.

That ability to bring horses to a peak performance might also explain a curiosity in O’Brien’s Breeders’ Cup record. The master of Ballydoyle is the most successful international trainer in the event’s history with 12 winners – tied with Chad Brown and trailing only U.S. Hall of Famers D. Wayne Lukas (20) and Bob Baffert (15). But just two of O’Brien’s winners were favorites, the 4-5 High Chaparral in the 2002 Turf (G1) and Mendelssohn at a lukewarm 9-2 in the 2017 Juvenile Turf (G1).

In fact, most of his Breeders’ Cup winners were well priced. Magician (2013 Turf) was 12-1, Wrote (2011 Juvenile Turf) was 11-1, George Vancouver (2012 Juvenile Turf) was 9-1, Hit It a Bomb (2015 Juvenile Turf) and Johannesburg (2001 Juvenile [G1]) were both 7-1, and three more went off at 6-1 – Found (2015 Turf), St Nicholas Abbey (2011 Turf), and Man of Iron (2009 Marathon). High Chaparral was the fourth choice at 9-2 when he repeated in the 2003 Turf (via dead-heat with Johar), and Highland Reel was the 7-2 third choice in the 2016 Turf.

The flip side of this picture is that O’Brien has also had his share of underlays who failed to perform. Usually these are two-year-olds, but occasionally others have offered poor value in circumstances that didn’t necessarily appear conducive to their best. Sometimes that’s clearer after the fact.

So how do you decide which O’Brien runners are most worth backing at the Breeders’ Cup? At the risk of generalizing, the key is to look for those with the greatest chance to move forward – whether entering on the upgrade or coming off an excusable loss, especially in unfavorable conditions. Those who have been at their peak for some time already might find it harder to maintain it. After all, they’re only flesh and blood, and even O’Brien can’t overcome the typical limits of equine physiology.

To sum up: Ballydoyle horses bring strong resumes that warrant respect, but rather than being overconfident in favorites, spot the better-priced ones that O’Brien might be conjuring up to new heights.