Horses train during morning workouts for the upcoming Breeders' Cup. (Rob Carr/Getty Images)

The most celebrated racehorses in the world will compete in the Breeders’ Cup races Friday and Saturday, but bettors shouldn’t let themselves be blinded by lofty reputations. The way to make money in this game is to look for vulnerability in favorites, and there may be several such opportunities at Churchill Downs.

I wrote earlier this week that I am highly skeptical of Uncle Mo, the morning-line favorite in the $5 million Classic. The 3-year-old possesses exceptional talent, but his season was disrupted by a serious illness and he lacks the seasoning to take on battle-tested older horses at 11 / 4 miles — a distance that might be a question mark for him under the best of circumstances. If these doubts about Uncle Mo are well-founded, the Classic could boil down to a two-horse race between Flat Out and Havre de Grace.

Havre de Grace is bidding to become America’s third straight female horse of the year. She never runs a bad race and she proved in the Woodward Stakes at Saratoga that she can beat top-class males. Flat Out, hampered by foot problems for much of his career, has blossomed as a 5-year-old, delivering four straight excellent efforts in New York, most recently a victory in the Jockey Club Gold Cup.

Havre de Grace beat Flat Out by 11 / 4 lengths in the Woodward, and the loser had no excuses. But Flat Out may be better suited to the Classic distance and he has been training especially well for the race. Daily Racing Form clocker Mike Welsch raved about the horse’s preparation and said he finished “like a freight train” in his final workout. Flat Out may have the edge over Havre de Grace, but I would box them in the exacta and use the two of them in sequential bets such as the pick three. The two races that precede the Classic — the Mile and the Juvenile — both feature standout favorites, but a venturesome bettor might take a shot at beating them.

Goldikova has been one of the most brilliant performers in the world over a span of four years; she has regularly beaten the best males in Europe and has won the Breeders’ Cup Mile three straight times. She’ll be a heavy favorite as she tries to make history by doing it again.

But her form doesn’t look quite so overpowering as it did in the past. The mare has finished second in three of her last four starts, and in her most recent race she lost to a rival who on paper didn’t look especially strong. I am no expert on European form, so I listen to the wise guys who are: A few days ago, the British bookmaking firm William Hill practically invited its customers to bet Goldikova by listing her as the tepid favorite at 2.25 to 1, with the English 3-year-old Strong Suit 2.75 to 1. I would use the two of them in the pick three along with Jeranimo, the 20-to-1 shot from California.

If trying to beat Goldikova is ambitious, taking a shot against Union Rags in the Juvenile may be utterly foolish. The 2-year-old has won all three of his starts authoritatively and he appears to tower over his rivals in this below-average field. But I am not yet convinced that Union Rags is so formidable; his speed figures — by the standards of previous Juveniles — are unexceptional, so perhaps one of his rivals could improve enough to pull an upset.

Hansen, winner of his two starts on the synthetic track at Turfway Park, could do it. When he captured the Kentucky Cup Juvenile, he beat negligible competition and earned a moderate speed figure. But he scored his front-running victory after setting blazing early fractions that were a full second faster than older male stakes horses recorded on the same day. Hansen is quick enough to jump out to an uncontested lead in the Juvenile. I’ll bet him in an exacta box with Union Rags, and use only the two of them in pick threes. (Not to mention the pick four, pick five and pick six — there’s no shortage of action on the Breeders’ Cup card.)

In other races that could produce a big payoff, the Turf Sprint has drawn a field with a surprising shortage of speed and will favor a horse who can race on or near the early lead. The 20-to-1 shot Country Day comes into the race after two troubled trips that make his form look bad, but with decent luck he’ll be in contention from the start. The Juvenile Turf is a crapshoot, but the U.S.-based horses look inferior to the Euros. The British invader Farraaj, listed at 15 to 1 in the morning line, has finished ahead of some good stakes winners in his last two starts.

The Friday card at Churchill, with six stakes serving as an appetizer for Saturday’s main event, does not appear to be a promising venue for bettors in quest of long prices. Secret Circle appears almost unbeatable in the Juvenile Sprint and My Miss Aurelia will be very hard to beat in the Juvenile Fillies. In fact, the only race of the day that looks wide open is the Juvenile Fillies Turf. The Grade I stakes-winning French invader, Elusive Kate, is the favorite, but Europeans have failed to win this event in its previous three runnings, and the North Americans in the field are a strong group. I’ll take a shot with DayattheSpa, who gave a gritty performance finishing second in a stakes at Woodbine and has an irresistible morning-line price of 12 to 1.