Over the years some handicapping trends have held up very well in the Kentucky Derby, while others haven’t been nearly as strong in recent years. Here’s a look at some of both kinds of Kentucky Derby trends:

Fewer than six career races - It is pretty close to a golden rule when it came to handicapping the Kentucky Derby that a horse had to have run at least six times in his career in order to be a legitimate contender for the roses. Since 1933 only four winners have run five or fewer times and still had the base of experience and stamina needed to win this race. Three of those horses had run five times, and Big Brown was a total fluke with just three career races. This year there is a solid chance that we will add another horse to the list because there are a fair number of inexperienced horses. We have to start with likely favorite Dialed In -- he has run just four times. Depending on your view that’s a serious warning sign, especially if he goes off at a low price. Midnight Interlude and Animal Kingdom join him with just four races, and Uncle Mo, Nehro and Shackleford have just five under their belt. There is a decent chance, then, that the top three betting choices will all be light on experience.

Fewer than three races as a three year old - It used to be another fairly solid rule that a horse had to race at least three times as a three year old to be ready to tackle the massive challenge of the Derby -- between 1937 and 2007 there were just six horses with fewer starts that had managed it. The credibility of that trend has been destroyed in the last three years, though, because Big Brown, Mine That Bird and Super Saver all won the Derby off of two starts. This year four horses are coming in with just two races this year -- Animal Kingdom, Stay Thirsty, Santiva, and Uncle Mo - and Master of Hounds has only raced once. Midnight Interlude has four races this year, but none as a two year old, so he has a different type of experience issue.

Layoff - Before Barbaro won the Derby it was widely believed that a horse needed to run no more than three weeks before the Derby or he wouldn’t be fresh and ready to run. Between Needles in 1956 and Barbaro in 2006 no horse won the race with four weeks or more of rest. After Barbaro, though, the floodgates opened -- Big Brown and Super Saver had extended rests as well. This year it’s almost expected that horses are coming off of long breaks -- fully half of the 20-horse field has been off since April 3 or longer. Even harder to believe, six horses ran their last prep race in March.

No prep race win - You’d think it would be hard for a horse to win this race if they hadn’t won a stakes race this year -- those stakes races have smaller, weaker fields than The Derby, so a horse that can win this race should be able to win lesser races as well. Remarkably, though, the lack of a stakes win as a three year old is far from a problem. Since 1980 there have been 11 horses that have won their first graded stakes of the year on the first Saturday of May. That’s good news for the eight runners this year who have yet to win a stakes in 2011.

Dirt experience - The one factor that has remained solid through the years is that it’s very hard to shine on the Derby dirt if you haven’t been successful on the dirt before. The Derby has been cruel to horses that have done well on turf or synthetics but don’t have dirt form as well. That trend will be tested in strange ways this year. Both Animal Kingdom and Master of Hounds have not only never raced on dirt, but have only recently had their first ever experience working on dirt. There are others with issues here as well. Derby Kitten ran just once on dirt and it was a disaster. The same is true for Twinspired. Brilliant Speed’s first two races were on dirt, and they were his two worst in eight career starts.

Trainers - You would think that a trainer making his debut in the Derby would be at a serious disadvantage because he doesn’t know what to expect or how to prepare a horse. That’s just not the case, though. In fact, being a rookie has been a good thing in recent years - seven of the last 11 winning trainers have done so with their first entrant. This year there are six trainers making their debut. Leading the way is Jinks Fires, the trainer of Archarcharch, who is 70 and has been training most of his life. He’s joined by fellow first timers Kathy O’Connell (Watch Me Go), Eddie Kenneally (Santiva), Kathy Ritvo (Mucho Macho Man), Jeff Bonde (Twice The Appeal), and Peter Miller (Comma To The Top).

Doc’s Sports expert Kentucky Derby handicappers will have a full card of Kentucky Derby picks for the Run for the Roses on May 7. Doc’s has been putting in extra work this year handicapping the Kentucky Derby field and we expect a big payday on Saturday. Get all Doc’s Kentucky Derby predictions for just $20! Click Here to purchase.