Bodemeister, the Bob Baffert-trained Arkansas Derby winner, drew the sixth post Wednesday and was installed as the 4-1 early favorite for Saturday's Kentucky Derby. Bodemeister will be ridden by Mike Smith, who piloted Giacomo to victory in the 2005 Kentucky Derby. The first event in US flat racing's Triple Crown drew a full field of 20 horses -- plus one. My Adonis, the 21st eligible colt, will get into the field if there is a scratch by Friday morning. Union Rags, trained by Michael Matz, drew the fourth post and was made the 9-2 second choice. "The horses around him maybe don't have that much speed, so that pushes us closer to where Bodemeister will be," Matz said. "It looks like it came up OK. We'll have to be running from the start." Matz won the 2006 Derby with Barbaro before the colt suffered a career-ending injury in the second leg of the Triple Crown, the Preakness Stakes. Liason, the second horse saddled by three-time Kentucky Derby winner Baffert, drew the 20th post. Gemologist, unbeaten in five career starts and trained by Todd Pletcher, was made the 6-1 third choice. He'll break from the 15th post under jockey Javier Castellano. Two of the colt's five victories have come at Churchill Downs. Pletcher also saddles El Padrino, who drew the 16th post and was priced at 20-1. The 1 1/4-mile Kentucky Derby is the first of the trio of races that make up the Triple Crown, along with the Preakness and Belmont Stakes. The last horse to complete the coveted treble was Affirmed in 1978.