LOUISVILLE, Ky. - For the second straight day at Churchill Downs, the annual array of festive Derby hats perched atop the heads of female patrons was useful for more than decoration yesterday.

The sky thundered and wept heavily in the morning, after a daylong drenching on Thursday, and those who dream of a crystalline setting for the most famous horse race in the world probably did the same thing.

Nevertheless, there will be a big race today, the 133d running of the Kentucky Derby. As of yesterday, it was even-money the Derby would be contested during rain. For a race always replete with variables, inclement weather would add another level of difficulty to the handicapping calculus of finding the best colt among a charging field of 20 high-strung thoroughbreds, each of which was bred, raised, and trained for exactly this moment.

Queen Elizabeth II, making her fourth visit to the United States, is expected to be in attendance today, fulfilling a long-standing desire to witness the spectacle.

The only sure thing is that security will be particularly stringent and the queen's humor and hat will remain dry, regardless of the conditions.

At the Derby, if nowhere else, even the queen of England will be able to more or less blend into the chaotic scenery, another celebrity drawn to the event, joining a long list that this year includes O.J. Simpson, numerous entertainment figures, and the guy who pulled away from the pack to capture the I-Fathered-Anna-Nicole's-Baby Stakes.

A year ago, the greatest celebrity to emerge from the Derby was the captivating, ill-fated champion Barbaro, owned by Roy and Gretchen Jackson of West Grove, Chester County, and trained in nearby Fair Hill, Md., by Michael Matz.

Barbaro won the Derby with a monstrous drive in the final stretch, pulling away to win by 61/2 lengths, the largest margin of victory since Assault won by eight lengths in 1946.

It was the kind of race that seemed to announce a horse capable of winning the Triple Crown, but Barbaro broke down in the opening furlong of the Preakness Stakes two weeks later. He underwent successful surgery on the injured hind leg at the University of Pennsylvania's New Bolton Center but eventually succumbed, after an eighth-month struggle, to the expected battle with laminitis that ensued.

It was not an uplifting story in the end, and part of Barbaro's special legacy is that it could be a while before another thoroughbred is received as fondly off the track or viewed as his equal on it.

The current crop of 3-year-olds doesn't offer a ready candidate, at least not yet. Perhaps at about 6:05 p.m. today that will change, but the forecast for this year's muddle in the mud is that some colt will definitely win but none will particularly stand out.

There are two Pennsylvania-bred horses in the field, although neither brings with it the sort of backyard Philadelphia connections that spurred local affection, in successive years, for Smarty Jones, Afleet Alex and Barbaro.

Great Hunter, a moderately interesting colt with an unfortunate (20th) post position, has changed hands twice and now is owned and trained in California.

Hard Spun, who is more impressive but prepped only against lightly regarded competition, got his first career win at Delaware Park and is owned by Wilmington resident Rick Porter. That is close enough for Philadelphia to root for, certainly, but not close enough to claim the horse as a homeboy.

The rest of the field is nearly indistinguishable, one from another, with only oddities to separate the horses. There is a colt blind in one eye (Storm In May), a colt named after a former slave (Curlin), five others that haven't won a race this year (Zanjero, Imawildandcrazyguy, Liquidity, Sam P. and Stormello), and five competing for the attention of trainer Todd Pletcher (Circular Quay, Scat Daddy, Any Given Saturday, Sam P. and Cowtown Cat).

From this mess, a worthy enough Kentucky-bred named Street Sense, winner of the Breeders' Cup Juvenile on this track last fall, has emerged as a slight betting favorite. His other two dips into Grade I races didn't result in wins, however. He was beaten by Great Hunter and Circular Quay in the Breeders' Futurity last year, and by Dominican, a 17-1 Derby medium long shot, in the Blue Grass Stakes in April.

Based on their short careers, Curlin is the only colt in the field that seems capable of developing into something very special. He didn't race as a 2-year-old, however, and has raced only three times this year (albeit three wins by a total of 28 lengths). That lack of experience makes traditionalists shudder, particularly considering the unusual demands of fighting through the jostling traffic for 11/4 miles and possibly eating mud while doing so.

It is an interesting mix, in some ways, and perhaps will produce a memorable Derby. If the track can dry out a little - yesterday's card was run in deep slop - maybe the horses will be able to run to form.

Either way, it seems a bit anticlimactic after Barbaro's triumph last year, even if the roses smell just as sweet this time around, even if the crowd still weeps when the band plays "My Old Kentucky Home," and even if the queen and O.J. get together to hit the trifecta.