04/28/2004 12:00AM

Zito's No. 3 now favorite

Imperialism, with trainer Kristin Mulhall aboard, blows out a quarter-mile Wednesday morning. He drew post 10 for Saturday's Derby.

LOUISVILLE, Ky. - At the beginning of the year, The Cliff's Edge was only the third choice among 3-year-olds in the barn of his trainer, Nick Zito. But while Eurosilver failed to even make the Derby, and Birdstone regressed this spring, The Cliff's Edge came to the fore. Wednesday, The Cliff's Edge was installed as the favorite to beat 19 other 3-year-olds in Saturday's 130th Kentucky Derby at Churchill Downs.

A victory in the Toyota Blue Grass Stakes, which followed a late-running third in the Florida Derby, has propelled The Cliff's Edge to the top of an inscrutable group of 3-year-olds. He is 4-1 on the morning line set by Churchill's Mike Battaglia, and is the 5-1 favorite on the line set by Mike Watchmaker, Daily Racing Form's national handicapper. The longest-priced favorite in Derby history is Harlan's Holiday, who went off at 6-1 in 2002.

The Cliff's Edge landed post 11 when post positions were selected Wednesday evening in the Kentucky Derby Museum during a one-hour telecast on ESPN. Shane Sellers, who is seeking his first Derby victory, will be his rider. The choice of 11 was curious. The field is loaded into the starting gate in pairs, meaning number 11 will be loaded first, along with number 1. Zito had the eighth pick overall. Still available were 14, the outside post in the main gate, or 15, the first stall in the auxiliary gate.

Zito acknowledged The Cliff's Edge would be among the first loaded. "I'm okay with that. I'd rather have that than fool around and get some other one," he said.

Smarty Jones, the unbeaten winner of the Arkansas Derby, wound up in post 15, and is the 9-2 second choice on the Churchill line. His trainer, John Servis, is participating in his first Derby, but showed shrewdness with his post selection.

"We wanted to force the hand of the other speed to go inside, and we liked the idea of being the first horse in the auxiliary gate," Servis said.

Tapit, the Wood Memorial winner, ended up in post 18. He is the third choice at 8-1. Lion Heart, who was second to The Cliff's Edge in the Blue Grass and is expected to be the early pacesetter in the Derby, will start from post 3. He is 10-1 on the Churchill line. Birdstone, the stablemate of The Cliff's Edge, is the highest price on Battaglia's line, at 50-1.

Patrick Biancone, the trainer of Lion Heart, chose post 3, 12 spots inside of Smarty Jones, rather than a post outside of Smarty Jones.

"I asked Mike Smith," Biancone said, referring to Lion Heart's jockey, "and he said he wanted to go inside."

The worst posts went to Limehouse, the third-place finisher in the Blue Grass, who ended up on the rail, and Quintons Gold Rush, the Coolmore Lexington Stakes winner, who will break from the outside, post 20.

If all 20 entrants run, the Derby's purse will be $1,214,800, with $914,800 going to the winner. All 20 runners race as separate betting interests. All carry 126 pounds. Smarty Jones will be adding Lasix for the first time.

The Derby could be run over a wet track. After several delightful, spring-like days, the National Weather Service predicted worsening weather. Saturday's forecast is for thunderstorms, and a high of 74 degrees.

The Derby draw for post positions is a two-step process. Wednesday morning, a blind drawing was held to determine the selection order of the 20 horses who made up the final field. Then, Wednesday evening, a representative of each horse picked a post. Minister Eric's connections had the first choice. His trainer, Richard Mandella, picked post 7. Quintons Gold Rush's connections had the final pick, and got the last remaining stall, 20.

There were 22 horses who wanted to run in this year's Derby. Under the Derby's rules, however, a maximum of 20 can run. When a field is oversubscribed, as it was Wednesday, the tie-breaker to pare the field is earnings in graded stakes. The two who were lowest on that list, and thus were excluded from the race, were Eddington and Rock Hard Ten. Value Plus, as expected, was not entered in the race, which allowed Pro Prado to move into the final spot.

Eddington most recently finished third in the Wood Memorial at Aqueduct. He had been training at Belmont Park. A plane was on hold in New York if he drew into the race, but trainer Mark Hennig kept him in New York when he learned Eddington was not going to crack the lineup. Hennig said he would point Eddington to the May 15 Preakness Stakes, the second leg of the Triple Crown at Pimlico.

"I'm just happy it's over because now I know where I'm going," Hennig said.

Had Eddington made it into the race, Jerry Bailey would have ridden him instead of Wimbledon. Bob Baffert, Wimbledon's trainer, would have had to scramble for a replacement. Baffert was warily eying his cell phone Wednesday morning for calls from Bailey's agent, Ron Anderson.

"Every time Anderson calls, I put it on block," Baffert said.

Rock Hard Ten also will be pointed to the Preakness, according to his trainer, Jason Orman. Rock Hard Ten was disqualified from second to third in the Santa Anita Derby, a decision whose monetary impact cost him a spot in the Derby. Orman was disappointed.

"To have a horse like this, with a chance to win the Derby, you'd like to run," Orman said. "He's doing so good. The last week, he's really come around. As long as he's training as good as he is, he'll train up to the Preakness."

Three Derby runners had short, quick workouts on Wednesday morning at Churchill Downs in final preparation for the race.

Action This Day zipped three furlongs in 35.20 seconds with his regular exercise rider, Paul Nilluang. Imperialism blew out a quarter-mile through the homestretch with his trainer, Kristin Mulhall, aboard. Song of the Sword worked a half-mile in 49.40 seconds with exercise rider Kevin Grau.

Tapit arrived Wednesday afternoon after a flight from Maryland.

Lion Heart will be the final Derby horse on the grounds. He has been training at Keeneland, and will be sent by van to Churchill on Saturday morning, Biancone said.

- additional reporting by Karen M. Johnson and Marty McGee