Mike Brunker Horse racing editor • Profile • E-mail

BALTIMORE - The 134th running of the Preakness Stakes on Saturday is dripping with intrigue, with the top four finishers in the Kentucky Derby spoiling for a rematch, jockey Calvin Borel abandoning the Derby winner and a couple of horse owners engaging in backroom machinations worthy of Boss Tweed.

But there is only one headline for this race, and it is that the fabulous filly Rachel Alexandra will make her first start against the males in the 1 3/16-mile Preakness, the second leg of the Triple Crown.

I’ve also instructed our sports editors to start working on clever headlines for after the race that go something like this: “Filly fantastic! Rachel Alexandra captures the Preakness.” That’s because she won’t just run against the boys, she will beat them.

Rachel Alexandra, the 8-to-5 morning line favorite in the race, is a rare bird. She’s as calm and smart as a thoroughbred racehorse can be and has the high cruising speed of a Maserati in fifth gear.

And the daughter of Medaglia d’Oro is on the verge of joining an even more exclusive club:  If she wins on Saturday, she would become just the fifth filly to win the Preakness and the first in 85 years, since Nellie Morse bested 14 rivals in 1924.

The biggest question surrounding Rachel Alexandra is just how good she is.

As Hall of Fame trainer D. Wayne Lukas noted Thursday at the Pimlico stakes barn, nobody knows because she really hasn’t been tested since she blossomed late last year. After running second in the Pocahontas Stakes on Nov. 1, she has reeled off five straight stakes victories, culminating in a jaw-dropping 20 ¼-length triumph in the Kentucky Oaks, the 3-year-old fillies’ equivalent of the Kentucky Derby.

More impressive than the margin of victory was the way she did it. Borel never moved his hands from the reins as she surged away from her overmatched rivals. He was carrying a whip, but on this trip it was just for decoration.

“I don’t think Rachel Alexandra, standing there in her stall, knows how good she is,” Lukas said jerking his thumb in the filly’s general direction.

The rest of us should have a better idea after Saturday, as Rachel Alexandra will likely have to work for her glory this time.

The biggest hurdle she’ll face will be in the form of a dozen well-muscled and accomplished 3-year-old colts and geldings, including Derby winner Mine That Bird and the three horses who chased him across the finish line in Louisville, Pioneerof the Nile, Musket Man and Papa Clem. Toss in beaten Derby favorite Friesan Fire, also-rans General Quarters and Flying Private and five fresh faces led by crack sprinter Big Drama and the improving Terrain and you have the makings of a quality field capable of pressuring Rachel Alexandra at several points in the race.

That would put the filly into unknown territory, as she hasn’t had to repel multiple challenges in a single race since her coming of age party in November.

But the defection of Borel from Derby winner Mine That Bird to Rachel Alexandra, whom he has ridden to victory in her last five races, speaks volumes. The fact that he was willing to cede the seat on the only horse with a chance of capturing the Triple Crown is a strong endorsement of the filly’s superiority.