05/12/2004 11:00PM

Just the right mix in a big colt


LEXINGTON, Ky. - The dark horse in the Preakness is almost pure black. His dark hide polished like obsidian, Rock Hard Ten glints blue, green, and gold as he goes across the track in the morning sun.

Unraced at 2 and one of two horses bumped from a position in the Kentucky Derby because of a lack of graded stakes earnings, Rock Hard Ten comes into the Preakness Stakes with much to prove but has the potential to be a tremendous racer.

By Kris S. out of the Mr. Prospector mare Tersa, Rock Hard Ten is an imposing colt, standing upward of 17 hands and sweeping across the track with an impressive stride.

He is the eighth foal out of Group 1 winner Tersa, who won the Prix Morny in France as a juvenile. A leggy and rather lightly made mare, Tersa was a $400,000 yearling purchase by Allen Paulson and was one of his best European-raced horses.

Since her retirement to breeding, however, Tersa has proved challenging to mate. None of Tersa's previous foals has shown the dam's racing ability. Rock Hard Ten is the mare's eighth foal and is her first racer of very high merit.

This situation has proven all the more frustrating because of Tersa's undoubted athletic ability and the racetrack successes in her immediate family. Tersa is out of the Jacinto mare Peacefully and is a half-sister to Kentucky Derby winner Gato Del Sol.

The unpredictability of genetic transmission has made a fortunate combination of traits in Rock Hard Ten.

In type and scope, Rock Hard Ten is quite like his paternal great-grandsire, Hail to Reason, but with more quality, thanks to the influence of Mr. Prospector and his high-class daughter Tersa.

Hail to Reason, a big and rather coarse son of Turn-to, was a very talented and progressive juvenile, when he won 9 of his 18 starts, including 6 of the last 7. Not surprisingly, Hail to Reason was champion 2-year-old colt of 1960. He broke down in a workout, which allegedly soured his trainer, Hirsch Jacobs, on using works to prepare his horses.

Jacobs was already a trainer whose general philosophy was to race them when they are ready, and his stock were noteworthy for tough limbs and strong constitutions.

Standing Hail to Reason at stud, Jacobs and his partner, Isidore Bieber, bred more tough horses with speed. Their greatest classic success in this vein was Preakness winner Personality, who was by Hail to Reason out of champion Affectionately, by Swaps. Also the winner of the Woodward, Jersey Derby, and Wood Memorial, Personality was not a notable success at stud.

Although Bieber and Jacobs bred many fine racers by Hail to Reason, none of that stallion's sons was as important and successful at stud as John Galbreath's European champion Roberto, who became a tremendous international success as a stallion at Darby Dan Farm, and Halo, who sired a pair of Kentucky Derby winners - Sunny's Halo and Sunday Silence - and stood most of his career at Stone Farm.

Whereas Halo improved with age, Roberto was a highweighted 2-year-old in Ireland, and the next year Roberto won the English Derby, then became the only horse to defeat Brigadier Gerard with a front-running effort in the Gold Cup at York.

A horse with more quality and finesse than Hail to Reason, Roberto proved an outstanding influence at stud, getting champions, classic winners, leading sires, and top broodmares. As an individual, Roberto showed some of the quality of Nasrullah, Bull Lea, and Blue Larkspur. Some of his progeny were built in the same mold, but others among Roberto's offspring got a strong dose of Hail to Reason.

Big, rangy horses with plenty of bone were characteristic of this group of progeny, which includes leading sires Dynaformer and Kris S. Dynaformer is still an active and successful sire at Three Chimneys Farm, while Kris S. died in 2002.

Along with all the resemblance to his paternal grandsire, Hail to Reason, Kris S. was a fast horse like that important sire, and Kris S. sired horses who had both speed and classic scope. His best racers include Prized, who won the Breeders' Cup Turf; champion Soaring Softly, who won the Breeders' Cup Filly and Mare Turf; Brocco, who won the Breeders' Cup Juvenile; and Kris Kin, winner of last year's Epsom Derby.

In addition, Kris S.'s daughter Hollywood Wildcat was a talented juvenile who came back at 3 to win the Breeders' Cup Distaff and earn a championship as the leading 3-year-old filly of her year. Out of the Mr. Prospector mare Miss Wildcatter, Hollywood Wildcat was bred on the same cross at Rock Hard Ten.