LOUISVILLE, Ky. - A 6-for-6 record and a chance to become the first unbeaten Kentucky Derby champion since Seattle Slew in 1977 wasn't enough to make Smarty Jones the early favorite for Saturday's race.

That role belongs to The Cliff's Edge, who was made the slight 4-1 favorite Wednesday. Smarty Jones, the Arkansas Derby winner, was second at 9-2. Tapit was the third choice at 8-1.

''It could have went either way,'' said Nick Zito, a two-time Derby winner who trains The Cliff's Edge. ''This probably will be the best betting Derby ever. I don't see any clear-cut favorite.''

By post time Saturday, though, Smarty Jones might just be the people's choice because of his humble background.

Smarty Jones comes from Pennsylvania, a state whose only Derby winner was Lil E. Tee in 1992. Trainer John Servis and jockey Stewart Elliott are based at small-time Philadelphia Park. Neither has been in the Derby before.

Smarty Jones almost died as a 2-year-old. He reared up and smashed his head on the iron starting gate, fracturing his skull and driving his left eye deep into his head.

Servis said he wasn't surprised Smarty Jones wasn't made the favorite.

''We took the route of least resistance. We only ran in one graded stakes,'' he said.

The colt drew the No. 15 post.

''We like the idea of being the first horse in the auxiliary gate,'' Servis said. ''It leaves a little bit of a margin for error in case he ducks in. It keeps him from getting squeezed off.''

Smarty Jones hasn't run as far as the 1 1/4 miles he'll have to handle in the Derby, but Servis isn't worried.

''I haven't gotten to the bottom of him yet,'' he said. ''I haven't been able to get him tired.''

Churchill Downs oddsmaker Mike Battaglia had a tough time picking between The Cliff's Edge and Smarty Jones.

''You can't knock Smarty Jones' record. The Cliff's Edge got a little bit better (speed) number in the Blue Grass,'' Battaglia said. ''Nick Zito has won the Derby twice and The Cliff's Edge has won two races at Churchill Downs. Very, very close, but that's what swung me.''

Zito couldn't believe the 50-1 odds - highest in the race - assigned to his other entry, Birdstone, the son of 1996 Derby winner Grindstone.

''50-1 is insane. I love Mike, but please,'' he said.

The Cliff's Edge won consecutive races at Churchill Downs in November. He's coming off a victory in the Blue Grass. Lion Heart, expected to set the pace in the Derby, was second, and Limehouse, another Derby horse, was third.

''The victory in the Blue Grass was a devastating win. Lion Heart didn't give up one inch and he just ran him down,'' Zito said. ''He's just getting better all the time. My good friend Bob Baffert says he likes him. Bobby Frankel says he likes him. That's pretty good confidence.''

A full field of 20 3-year-olds was entered for the Derby. The last time 20 horses started was 1984. That year a rule was made to cap the field at 20, and since then the maximum has yet to be reached.

Like Zito, Hall of Fame trainer Richard Mandella has two starters in a bid for his first Derby win: Breeders' Cup Juvenile winner Action This Day and Minister Eric. Juvenile winners have failed to win the Derby 19 times.

Lion Heart was the fourth choice at 10-1. Master David, trained by Frankel, and Read the Footnotes were the co-fifth choices at 12-1.

''I just played it safe and picked someplace in the middle,'' Frankel said of the eighth post. ''The race will set up with Lion Heart going to the lead. What Smarty Jones does will dictate the whole race.''

Four horses were at 15-1: Friends Lake, Imperialism, Wimbledon and Santa Anita Derby winner Castledale.

Three-time Derby winner Baffert selected post five for Wimbledon. Baffert's horse, War Emblem, started there in 2002 and won; last year's winner Funny Cide also broke from No. 5.

''I wanted an inside post. I was hoping to get the five,'' Baffert said. ''He's the kind of horse that's going to be following, he'll be back in the pack somewhere.''

Tapit will break from the No. 18 post. Trainer Michael Dickinson didn't have much choice with the 16th selection.

''It's a long way out, right at the hot dog stand,'' he said.

''Why didn't you take the one-hole?'' Frankel asked.

''We didn't want to be that close to the rail,'' Dickinson said.