ARCADIA, Calif. - After Rachel Alexandra dominated much of the U.S. racing season, it is finally Zenyatta's moment to take center stage. The 5-year-old mare, who has won all 13 of her races with a powerful late kick, will face males for the first time when she runs Saturday in the Breeders' Cup Classic. Zenyatta is the biggest star in two days of racing at Santa Anita that include 14 stakes with more than $25 million in purse money. But there are substantial reasons to doubt that she can beat male rivals as Rachel Alexandra did in the spring and summer. Trainer John Shireffs has given Zenyatta an ultra-conservative campaign this season, racing her four times on the synthetic tracks she loves, always against small fields of overmatched fillies and mares. Zenyatta didn't blow away this competition, and her speed figures were unexceptional. Her modest winning margins were partly the result of her catch-'em-at-the-wire style, but nevertheless she has not looked as impressive as she was in her best efforts of 2008. It requires a giant leap of faith to conclude, from her 2009 form, that Zenyatta can beat a Classic field that includes the best U.S. males - Summer Bird and Quality Road - and a pair of high-class Europeans. It is preposterous that she is the 5-2 morning-line favorite. Zenyatta's main advantage is that she has proved herself on synthetic tracks while her principal rivals have not. This is an issue that handicappers will confront in every Breeders' Cup event on Santa Anita's Pro-Ride surface: How do you evaluate horses such as Summer Bird and Quality Road who have never raced on a synthetic track? How do you view European turf specialists running on Pro-Ride? The 2008 Breeders' Cup at Santa Anita provided limited but clear evidence with which to answer these questions. Dirt specialists who were unproved on synthetics were unable to win, but turf horses made the transition effectively. The best American filly sprinter, Indian Blessing - almost unbeatable on dirt - lost to the turf specialist Ventura. Europeans ran one-two in the Classic. The major prep races for this year's Breeders' Cup added more support to this premise: On a synthetic track, disregard the dirt runners and respect the turfers. That will be my strategy for the entire Breeders' Cup. If the 2009 Classic had been run on dirt, Summer Bird and Quality Road would have been the standouts. On Pro-Ride, I'm throwing them both out. I'll take a stand against Zenyatta. I'll throw out all of the males who have been racing well on the California synthetic tracks. (They're a mediocre lot; a third-rate European invader beat the Californians in the recent Goodwood Stakes.) That leaves the two European entrants, Rip Van Winkle and Twice Over. Rip Van Winkle won two straight Group 1 stakes in England after losing by a length to the continent's superstar, Sea the Stars. He - not Zenyatta - is the class of the Classic field. The difficulty of comparing horses' performances on different surfaces, and of comparing European form with U.S. form, makes many of the Breeders' Cup races very difficult. But at least a couple of them appear clear-cut: * Sprint: Zensational, the California-based front-runner, is a 7-5 favorite in the morning line. Many bettors looking for an upset scenario think that Zensational could get into a suicidal duel with the speedy Fatal Bullet, and thus set up the race for one of several stretch-runners in the field. This popular view of the Sprint is wrong. Fatal Bullet is the fastest and best horse in the field, and he is going to dominate Zensational. Zensational has scored his three stakes victories by getting loose against moderate fields without serious early pressure. In none of them has he run his opening quarter-mile faster than 22 seconds. By contrast, Fatal Bullet has encountered fast front-runners in almost all of his races. Last year, he dueled through the first quarter-mile of the Sprint in 21.28 seconds and held to finish second. That was the only time in 10 starts that he has lost a synthetic-track race at 6 1/2 furlongs or less. The Sprint field is traditionally filled with speedsters who produce a destructive fast pace. But some of the country's best sprinters have bypassed this event because they are dirt specialists ill-suited to the Santa Anita track. Fatal Bullet won't have to work as hard as he usually does in order to get the lead. I'll play him in exactas on top of the stretch-runners Gayego and Capt. Candyman Can. * Dirt Mile: The most formidable milers at Santa Anita this weekend have been entered in the Classic, where they can shoot for a $5 million purse instead of $1 million in the misnamed Dirt Mile. Six of the nine U.S. runners in this event have never won a stakes on a synthetic track. Against such a weak lineup, Mastercraftsman is a standout. The Irish runner has faced the best competition in Europe and has won four Group 1 stakes; he tuned up for his visit to Santa Anita by winning a race over Polytrack by five lengths. He deserves to be a short-priced favorite and probably will be. The logical exacta horse is probably Bullsbay, but there will be good value on Furthest Land, who is 2 for 2 on synthetic tracks, earned a high speed figure in his last start, and is 20-1 in the morning line. (c) 2009, The Washington Post