Is she 'Alexandra' the Great?

Say hello to Rachel Alexandra, the 3-year-old filly who has bumped Kentucky Derby winner Mine That Bird out of the spotlight - at least temporarily - for Saturday's 134th Preakness Stakes.

Make no mistake, Mine That Bird is still a story, after winning the Derby by the largest margin (6 3/4 lengths) in more than 60 years, as a 50-1 shot. The son of former Belmont Stakes winner Birdstone will always be talked about with wonder because of what he did on the first Saturday of May in 2009.

What better Cinderella story is there than to win a race in which you were last at the 3/4-mile mark and 12th at the mile mark, tallying by the largest margin since Assault won the 1946 Derby by 8 lengths?

But the prerace chatter is about Rachel Alexandra, who prepped for the Belmont by winning the Kentucky Oaks two weeks ago by a whopping 20 1/4 lengths, with jockey Calvin Borel proclaiming her the best horse he has ever ridden.

This, of course, is the same Calvin Borel who has ridden two Kentucky Derby winners - Street Sense in 2007 and Mine That Bird.

And thus begins the controversy. How often does the jockey of the Derby winner switch horses for the Preakness? Try never. Although the Derby winner has switched jockeys for the Preakness three times, Borel will be the first jockey to ride the Derby winner and then ride another horse in the Preakness.

"I had no choice," said Borel, who has been Rachel Alexandra's regular rider. "She's something else."

Yes, she is, which makes the story even more intriguing, considering that a week ago Rachel Alexandra's career path had her only flirting with the boys.

Then she won the Oaks in such a dominating fashion that the boys vs. girl chatter increased, and so did interest in her as a potential brood mare down the line. The plan is to breed her with the 2007 and '08 Horse of the Year Curlin when her racing career is over.

Original owner Adolphus Morrison, who named the horse after his granddaughter, had indicated that if Rachel Alexandra did run against the boys, it might be later in the year, perhaps at the Travers at Saratoga in August, not in the supercharged atmosphere of the Triple Crown season. But then a group headed by Jess Jackson made an offer to buy Rachel Alexandra that Morrison couldn't refuse - speculation has the total as much as $12 million. Jackson has only said that the price tag of $3 million in some reports is very low.

Just like that, the deal was done and Rachel Alexandra had new owners, a new trainer in Steve Asmussen, and a new direction. On Monday, the paperwork was filed, entering her in the 13-horse field for the Preakness, without the objections some of the other owners had previously expressed.

One who originally was against Rachel Alexandra running in the Preakness was Mine That Bird co-owner Mark Allen, who was stung twice, by seeing a serious contender entered in the race, as well as losing Borel as his jockey. (Rachel Alexandra was the morning-line favorite at yesterday's draw at 8-5 and will race from the No. 13 post).

Allen was considering running Indy Express in the Preakness field in the hopes of preventing Rachel Alexandra from making a field that is limited to 14 horses, but decided against it.

"My decision to enter Indy Express in the Preakness was strictly business," said Allen in a statement earlier this week, "but after consulting with my dad and [co-owner] Doc Blanch, I have decided to withdraw Indy Express to prevent any further misunderstandings. Their advice to me was to do what's right, because arrogance and greed isn't right."

When Jackson paid the $100,000 supplemental fee, the deed was done. Rachel Alexandra was running in the Preakness with Borel aboard. Allen, making a quick change, found Hall of Fame jockey Mike Smith to ride Mine That Bird.

Having Rachel Alexandra in the field brings up other concerns. A year ago, trainer Larry Jones entered highly touted filly Eight Belles in the Kentucky Derby. She ran a gallant race behind winner Big Brown and then broke down and had to be euthanized on the spot. Genuine Risk won the Derby in 1980 but finished second in the Preakness, and fellow filly Winning Colors won the 1988 Derby and finished third in the Preakness.

Gary Stevens, who is now an NBC racing analyst, was the jockey on Winning Colors and sees potential greatness.

"Rachel Alexandra makes goose bumps stand up on the back of my neck," said Stevens, "like a good racehorse used to when I was on her back."

Two years ago, Rags to Riches became the first filly to win the Belmont since 1905. It was essentially the punctuation mark on her career.

Now, it is Rachel Alexandra's turn. She is bigger than many of the horses in the Preakness field, including Mine That Bird, and has both come from off the pace and set her own pace. No filly has won the Preakness since Rhine Maiden won in 1915 and she is the only winner of the Kentucky Oaks to ever run in the Preakness.

And she goes into the Preakness as the prohibitive favorite.

Jackson sounded optimistic after yesterday's draw. "This isn't about male or female," said Jackson. "Fans deserve to see the best horses, regardless of sex. She's a perfect athlete. She has good recovery. She didn't burn herself out in the Oaks. We might as well find out and define her. If she can compete in this race, the boys will have their hands full."

Jackson also sees a bigger picture. "I hope this revives horse racing in the United States," he said.

Mark Blaudschun can be reached at blaudschun@globe.com.