Whether a byproduct of skill or luck, selecting the right horse in America’s most famous horse race is the goal for any observer. And Saturday’s 137th running of the $2 million Kentucky Derby sets up to be quite a challenge.

The road to the 2011 Kentucky Derby has lacked clarity, with major upsets in the Arkansas Derby (G1), Blue Grass Stakes (G1), Santa Anita Derby (G1), Louisiana Derby (G2) and Wood Memorial (G1) as well as a slower-than-expected winner of the Florida Derby, and that makes it difficult to separate the top contenders.

The race feels wide open, with more than half of the 20-horse field having the potential to wind up in the winner’s circle, and it’s essential to identify an improving three-year-old with the proper credentials to deliver a career-best performance. But one can’t escape the likelihood that racing luck will play a key role in the final equation.

Overview

Let’s start with the specifics, namely the 1 ¼-mile distance at which each horse will be tested for the first time. Pedigree analysis indicates whether a horse is suited for the trip.

Horses with favorable bloodlines for the Derby distance include Animal Kingdom, Brilliant Speed, Dialed In, Master of Hounds, Midnight Interlude, Nehro, Stay Thirsty and Twinspired.

In terms of the race set-up, the Derby lacks a true speedball who figures to sprint clear from the start, but five horses – Comma to the Top, Decisive Moment, Pants on Fire, Shackleford and Soldat – could break running for the early lead. A contested pace battle would set up well for a late runner, whether from midpack or the caboose of the field.

Speed ratings are an important handicapping tool, with top Derby contenders typically earning century-topping numbers in their prep races, but this isn’t the fastest crop of three-year-olds. From this year’s races, only three entrants – Dialed In, Shackleford and Soldat – have a triple-digit BRIS Speed rating to their credit, so the barometer is lower in 2011. Horses with speed ratings in the upper 90s can’t be dismissed from win consideration.

I will separate the Derby field into three categories, listing alphabetically in each, before giving my final selections.

Impossible to recommend

BRILLIANT SPEED showed decent form on the turf at Gulfstream Park this winter, placing in a couple of listed stakes, before taking his game to a new level on Keeneland’s Polytrack, registering a 19-1 upset in the Blue Grass. But that means little in terms of dirt form. Horses based on turf or synthetics haven’t fared well in the Kentucky Derby and Brilliant Speed appears out of his element.

COMMA TO THE TOP won’t sustain his speed at 1 ¼ miles. Bred for sprints on both sides of his pedigree, he’s run out of gas in both starts at 1 1/8 miles this year and would need a breather on the front end to have any chance at lasting the entire way. That’s not going to happen in the speed-laden field.

DECISIVE MOMENT received an unfavorable draw in post 5. With all the speed to his outside, he’ll have to gun it from the start or risks getting shuffled back in traffic. He’s facing a steep class hike with a number of drawbacks, including lower speed ratings and a questionable pedigree for the distance.

DERBY KITTEN belatedly made the field when Toby’s Corner failed to ship in Tuesday and his participation makes little sense based upon his form. Drilled by 27 ½ lengths in his lone dirt start, he’s better suited for turf/synthetic racing.

TWICE THE APPEAL has three-time Derby winner Calvin Borel, but the Kentucky Derby maestro will come up empty this year. Available for a $30,000 maiden claiming tag in late December, Twice the Appeal couldn’t win the Turf Paradise Derby two starts back and finished slowly when springing a 25-1 upset in the Sunland Derby (G3). He won’t be a serious factor at this level.

WATCH ME GO earned his way into the field with a 43-1 upset in the Tampa Bay Derby (G2) over his home track two starts back, but flopped miserably against soft rivals in the Illinois Derby (G3). He drew a terrible post (20) and looks too slow to challenge.

Fringe contenders

ANIMAL KINGDOM lacks dirt experience, but he turned in a sharp six-furlong workout over a fast track last week and could be dangerous if he transfers his stellar turf/synthetic form to the main track. The chestnut owns a ferocious late kick and should run all day with his pedigree. And he’s in good hands with horseman Graham Motion. Difficult to envision him winning, but Animal Kingdom (30-1 morning line) could add value to the bottom of exotic wagers.

MIDNIGHT INTERLUDE doesn’t have history on his side -- Apollo was the last unraced two-year-old to win the Derby in 1882 – but the late-starting colt is trained by three-time Derby winner Bob Baffert and stamped himself as one to watch with his upset in the Santa Anita Derby, his first start against winners. Midnight Interlude is training well at Churchill Downs and will look to settle in midpack before offering his best, but a minor award is probably the best-case scenario for the inexperienced colt.

PANTS ON FIRE jumped forward with a career best in the Louisiana Derby, surprising with a front-running victory, and needs to be forwardly-placed to have any chance in the Derby. He’ll break from post 7 with Anna “Rosie” Napravnik, a rising star who is attempting to become the first winning female jockey, and Pants on Fire has attracted positive attention during his morning drills at Churchill Downs. Still have a difficult time getting past his prior form, but the improving colt remains a threat to challenge for the top three if he handles the class hike and extended distance.

SANTIVA got little out of his final prep race, a troubled ninth in the Blue Grass, but he ran well when opening 2011 with a second in the Risen Star (G2) and captured the Kentucky Jockey Club (G2) last November, Churchill Downs’ premier race for two-year-old males in the fall meet. He received a favorable draw in post 12, but his Speed ratings are a little light. Not convinced he’s ready to deliver a top showing at 1 ¼ miles, but won’t dismiss his chances completely.

SHACKLEFORD nearly stole the Florida Derby on the lead at 68-1 and has left a favorable impression in his morning preparations for the Derby. The well-built colt avoided the potential pratfall of an inside starting position when drawing post 14, and Shackleford broke his maiden at Churchill Downs last November. Worried about the possibility of a regression off a career-best last time, as well as his top-side breeding for 1 ¼ miles, but he’s an up-and-coming runner with a bright future. A good trip could put him in the mix turning for home.

STAY THIRSTY possesses a much better pedigree for the distance than stablemate Uncle Mo, the two-year-old champion who was scratched Friday morning. A good second in the Hopeful S. (G1) at two, he opened his three-year-old season with a nice win in the Gotham (G3) but flopped when adding blinkers for the April 3 Florida Derby. Trainer Todd Pletcher will remove the headgear and Stay Thirsty figures to drop back in order to make one run. He appears to own plenty of room for improvement and is definitely capable of better than he showed last time, but not sure he’s ready for a career-best on the first Saturday in May. Stay Thirsty still rates as a potential Derby sleeper.

TWINSPIRED didn’t look like a Derby contender when competing in listed stakes at Turfway Park this winter, but he’s come on in his last two starts, finishing third in the Spiral S. (G3) and a nose second in the Blue Grass. He owns a commendable pedigree for 1 ¼ miles on dirt and could sit into a good stalking trip in midpack with his tactical speed, but the gray colt has been racing mostly on synthetics. Twinspired remains an outsider, but he’s eligible to rally into the mix if he handles the change from synthetics to dirt.

Major threats

ARCHARCHARCH enjoyed a terrific campaign at Oaklawn Park, capturing both the Arkansas Derby and Southwest S. (G3), and has trained spectacularly since arriving on the grounds at Churchill Downs. The nearly black colt owns the right running style, with the ability to rapidly advance into contention on the far turn, and was under serious consideration for top honors before being severely compromised by the rail post. Too much can go wrong from that starting position, but Archarcharch remains a dangerous win candidate if he somehow avoids trouble during the early stages.

DIALED IN looks very capable of giving trainer Nick Zito his third Derby winner. He won his career debut at Churchill Downs last fall and has posted a pair of triple-digit BRIS Speed ratings this season, winning both the Florida Derby and Holy Bull (G3). A one-dimensional late runner, Dialed In likes to circle rivals with his powerful strides, but he risks losing a lot of ground or being stopped in traffic in a 20-horse field. He’s also a very inexperienced colt with only four career starts. But those potential drawbacks could prove meaningless if he gets the trip.

MASTER OF HOUNDS is a mystery on dirt and the Irish colt will be attempting to become only the second foreign-based runner to capture the Kentucky Derby (Canonero II won in 1971). But the Americans haven’t necessarily distinguished themselves and a top-class Euro invader has a chance to strike if he handles the main track. Group 1-placed on turf at two, Master of Hounds recorded an outstanding effort when opening 2011 in the March 26 U.A.E. Derby, missing by only a nose to a superb rival, and he figures to move forward off the strong showing. The pedigree is there and leading trainer Aidan O’Brien knows how to point for a major target, and Master of Hounds rates as an intriguing contender at long odds (30-1 morning line).

NEHRO wasn’t on any Derby radar screens when breaking his maiden on February 21, but he’s rapidly advanced since his lone victory, posting a neck second in both the Louisiana Derby and Arkansas Derby. The latter was extremely impressive, with Nehro blowing right by the winner one jump after the finish line, and his BRIS Speed ratings are increasing (88-96-99). The Steve Asmussen colt fits our criteria – an improving three-year-old who appears ready to put it all together with a career-best in the Derby – and the race will set up well for the late runner. Also like the fact that he was able to extricate himself from trouble in upper stretch of the Louisiana Derby before finishing full of run. That ability to maneuver could serve him very well in a bulky Derby field, and Nehro could be along in time under Corey Nakatani.

MUCHO MACHO MAN displayed class at two, finishing second in both the Remsen (G2) and Nashua (G2), and will enter the Derby off two positive efforts this year, winning the Risen Star prior to a close third in the Louisiana Derby. In the latter, the physically imposing colt ripped out a piece of his foot when losing a shoe at the break and never quit trying despite the discomfort. Trained by heart-transplant recipient Kathy Ritvo, the sentimental favorite has a lot going for him and could offer a formidable rally from just off the pace.

SOLDAT romped in the Fountain of Youth two starts back but got shuffled back early in the Florida Derby and failed to challenge. He doesn’t want to be behind horses in the Derby, so look for him to establish a forwardly-placed position from the start, racing on or very close to the lead from post 17. Love the fact that he has three starts at 1 1/8 miles this year and any moisture in the track only enhances his win potential. Trainer Kiaran McLaughlin nearly captured the 2005 Derby, finishing a close second with 71-1 longshot Closing Argument, and the top horseman has a more talented colt at his disposal this year. Soldat owns a pair of triple-digit BRIS Speed ratings this year and merits serious respect.

UNCLE MO, a superstar at two, didn’t appear to be coming into the Derby the right way, with too many questions about his health and fitness, and his connections opted to scratch him from the race.

Predictions

1) Nehro – Rallies boldly in the stretch to win the Roses

2) Dialed In – Offers strong late showing before settling for second

3) Master of Hounds – Threatens to win turning for home but can’t hold off the closers

4) Soldat – Prominent throughout but comes up a little short in the end

5) Archarcharch – Game effort despite rough trip; rail post proves too much to overcome

Enjoy the Derby!