Part of what makes the Kentucky Derby so fascinating is that there are so many characters involved. The horses are obviously crucial, but they can’t accomplish anything without the hard work of the trainers and the jockeys. Here’s a look at some of the 2013 Kentucky Derby trainers who will factor heavily into the betting decisions for this year’s race:

Todd Pletcher (Verrazano, Revolutionary, Overanalyze, Palace Malice, Charming Kitten)

Pletcher will have, barring injuries, fully a quarter of the horses in the Kentucky Derby field. Verrazano has been the favorite for weeks heading into the Derby. He’ll be challenged by others — including Orb, Goldencents, and Pletcher’s own Revolutionary — for favoritism by post time. Pletcher has a strong group of horses this year. This isn’t the first time he has had a lot of runners, and it hasn’t led to a lot of recent success. Pletcher has just one win — Super Saver in 2010 — in 31 tries. That’s a pretty pathetic 3 percent winning percentage. He has finished dead last five times in the race and has finished better than sixth just once in his last 17 starts in the race. For a guy who has led the nation in earnings seven times since 2000, and leads again this year, the lack of success in the Derby is mystifying. It also forces anyone who bets on him to be more nervous than they might normally be.

Shug McGaughey (Orb)

McGaughey is a true legend in the sport — a hall of famer. He has won hundreds of stakes races, including nine Breeders’ Cup victories. Despite all of his success, though, he is a rare sight on the Triple Crown trail. The trainers that are often in the Derby are high-volume guys. McGaughey is far more patient and only brings a horse when it is ready. He won the Belmont in 1989 with Easy Goer, but his Derby success is limited. He has a very good one in Orb, though, and it is telling that a guy who has seen and done all that he has is as excited about his chances as he seems to be.

Doug O’Neill (Goldencents)

The defending Derby and Preakness Champion isn’t going to win any man of the year awards. O’Neill has won his share of big races through the years, but he also leads the country in positive drug tests and generally shady practices. Because of his history of abuses, there is doubt among the critics every time a horse is entered. Conspiracy theorists even suggested that I’ll Have Another was scratched for the Belmont last year not because of an injury as O’Neill claimed but because increased security made it impossible for him to medicate as he prefers. What O’Neill does have going for him, though, is he knows how to deal with the intense scrutiny and chaos of the Derby.

Chad Brown (Normandy Invasion)

Brown is one of the younger trainers on the big stage — he was only born in 1978. He apprenticed under Bobby Frankel before going out on his own in 2007, and he won his first of two Breeders’ Cup races the next year. His rise has been meteoric. He was fifth in the nation in earnings last year, and he is in the Top 10 again this year. This will be his first Derby starter.

Rudy Rodriguez (Vyjack)

Like Brown, Rodriguez also used to work for Frankel. It was another former boss, though, that almost cost Rodriguez his chance to be in this race. The trainer needed a special hearing to get a license in Kentucky because of problems working under Dutrow back in 2007. Dutrow was a notorious drug cheat, and Rodriguez was implicated in some of the issues. He was eventually licensed, though the horse is under constant video surveillance while at Churchill Downs. Rodriguez, a former jockey, has an advantage over most other trainers — he exercises his own horses most of the time, so he gets a firsthand feel of how they are doing and what they need.

D. Wayne Lukas (Oxbow, Will Take Charge)

Lukas is an all-time legend. He has 13 Triple Crown wins, including four Derby victories. His best days are far behind the 77 year old, but he is enjoying a mild renaissance lately. Neither of his two contenders this year will threaten for favoritism. Oxbow has trained well up to the race, though, and could be dangerous if he can shake the lousy racing luck that has plagued him this year. Lukas and jockey Gary Stevens team up on that horse in a pairing that thrills nostalgic race fans like me. The two combined to win the Derby in 1988 with Winning Colors and again in 1995 with Thunder Gulch. Stevens just this year returned to racing after forced into early retirement with bad knees.

Aidan O’Brien (Lines of Battle)

O’Brien will be looking to do what no trainer has managed so far — winning the Derby with a horse not based in the U.S. for at least part of his three year old season, Lines of Battle has been racing in Dubai. O’Brien is the private trainer for Ballydoyle Stables, one of the top racing operations on the planet. Based in Ireland, they race all over the world and have won major races in Dubai, across Europe and in North America. He has never been a factor in the Derby, though, and finished dead last with Daddy Long Legs last year.

Read more articles by Trevor Whenham