LOUISVILLE, Ky. - Churchill Downs becomes a playground for the rich and famous every May, making stargazing as popular as handicapping. This year's celebrity lineup at the Kentucky Derby will be trumped by royalty.

Queen Elizabeth II.

The British monarch, a horse enthusiast, will attend her first Derby on Saturday - adding another chapter to a race steeped in tradition in a sport where bloodlines are valued.

A number of track workers attended etiquette class to avoid any social faux pas when in the queen's presence. The track's executive chef planned a sumptuous Southern-style meal featuring Kentucky favorites.

The queen and her husband, Prince Philip, will attend the 133d Derby as part of a six-day trip to the United States that also includes visits to Virginia and Washington.

The queen has stabled horses at Kentucky farms in the past. She visited the Bluegrass State four times between 1984 and 1991 but has never been to Louisville.

This won't be the first time British royalty has attended the Derby: Princess Margaret, sister of the queen, attended the 1974 Derby with her husband, Lord Snowdon.

Stormy weather. Rain started falling at Churchill Downs yesterday, and a wet pattern is expected to continue through Derby Day. The forecast calls for a 30 percent chance of rain Saturday. The good news: The weather should remain warm throughout the period, hitting 79 degrees for the Derby.

Finish lines. The last two Derbies were won by horses with seven-letter names that ended in O - Giacomo and Barbaro. The only horse that fits the pattern this year is Zanjero.

Edgar Prado, who rode Barbaro last year, will try to become the fifth jockey to win consecutive Derbies. Isaac Murphy was the first to pull off the Derby double with Riley in 1890 and Kingman in 1891. Jimmy Winkfield did so with His Eminence (1901) and Alan-a-Dale (1902).

There was a long gap until Ron Turcotte did it in 1972-73 with Riva Ridge and Secretariat. Eddie Delahoussaye was the last with Gato del Sol (1982) and Sunny's Halo (1983). Prado rides Scat Daddy on Saturday.