Some trainers would love to saddle just one horse in the Kentucky Derby in their career.Todd Pletcher will have five in the one coming up. Maybe even a record six."I have a tremendous appreciation for how difficult the Kentucky Derby is to win," said the trainer, who has had better luck at just about every other big-money race. "Even if you have the best horse, a lot of times that doesn't mean you're going to succeed."He should know.He is 1 for 31 in the Derby, which goes off Saturday, and five times since 2000 the last-place finisher came from his barn.Three years ago, Pletcher ended an 0-for-24 skid when longshot Super Saver, one of four horses he entered, won under Calvin Borel.Borel is back this year and will ride Revolutionary.A full field of 20 horses is expected for the 11/4-mile race at Churchill Downs."You have to have everything go right on the day and during the race, and get lucky with the weather, and the track condition, and all those things," Pletcher said. "But all that being said we couldn't be more happy with the cards that we're holding at the moment."His ace is Verrazano, undefeated in four starts this year including a three-length win March 9 in the Tampa Bay Derby. The colt will try to buck a Derby jinx: No horse since Apollo in 1882 has won it without racing as a 2-year-old."Based on the way the horse has trained for us all winter, he's given me the impression that I've never really seen the bottom of him, so that's very encouraging to me," Pletcher said.Besides Verrazano and Revolutionary, his other entries include Overanalyze, Palace Malice and Charming Kitten. And maybe Winning Cause, too.Pletcher's mentor, D. Wayne Lukas, 77, has a shot at Derby history. The Hall of Famer could become the oldest trainer to win with either Will Take Charge or Oxbow. The four-time Derby winner would surpass Charlie Whittingham, who was 76 when Sunday Silence won in 1989."I don't feel any different than when I came in here at 50. There's still the adrenaline rush," Lukas said. "…The horse is the most important ingredient. You better have the horse and then some luck."Bob Baffert, a three-time winner and Hall of Famer, is back, too. He finished second last year with Bodemeister, and this time saddles Governor Charlie.Hall of Famer Shug McGaughey, who hasn't won in his last six tries, will send out Florida Derby winner Orb.This year's road to the Derby trail claimed a few contenders, including two Pletcher horses — Breeders' Cup Juvenile winner Shanghai Bobby and Violence.Trainer Doug O'Neill goes for consecutive wins, bringing Santa Anita Derby winner Goldencents a year after I'll Have Another pulled off the upset at 15-1 odds.