05/03/2007 12:00AM

Nafzger's savvy gives Street Sense an edge


WASHINGTON - In Saturday's Kentucky Derby, one of three scenarios is likely to unfold:

* Street Sense will win by duplicating the performance he delivered last fall to run away with the Breeders' Cup Juvenile and become the champion of his generation.

* Curlin, undefeated and untested in three career starts, will overcome his lack of experience and establish himself as a brilliant 3-year-old star.

* Somebody else will win, most likely by benefiting from good racing luck, and will be regarded as the best of a undistinguished bunch. The winner might be another Giacomo, whose slow victory in 2005 (and subsequent trouncing in the Preakness and Belmont Stakes) established him as one of the weakest Derby winners of recent decades.

The records of many entrants in Saturday's race look superficially good: They have performed consistently and won major stakes this year and last. But they haven't been running fast, and that is the best measurement of horses' talent. The average winning Beyer Speed Figure for the Derby is 109, and in many years the top contenders have already run that fast going into the race. In this field, nine of the entrants have a top figure as a 3-year-old between 100 and 103, a range that is the equivalent of less than two lengths. On the basis of these numbers, the 133rd Derby appears to be a toss up. In overall quality, it's pretty Giacomo-like.

Curlin could alter the view that this is a subpar crop of 3-year-olds, for he has scored his three victories in a manner suggesting he has unlimited potential. He won his last start, the Arkansas Derby, by 10 1/2 lengths. But horses don't win the Derby on the basis of potential. With only three starts since he launched his career in February, he doesn't have enough seasoning to win the Derby. As I wrote previously, I will throw him out.

Because the entrants are so evenly matched, based on their 2007 form, I want a horse who has the type of solid preparation and seasoning that usually characterizes Derby winners. I don't want Circular Quay (runner-up in the Breeders' Cup Juvenile), whom trainer Todd Pletcher has chosen to bring into the Derby off an eight-week absence from competition, a strategy that defies all the lessons of history. I don't want Hard Spun (the winner of 5 of his 6 starts), whose trainer Larry Jones vacillated for weeks about whether he should run in the Derby. I don't want Tiago (winner of the Santa Anita Derby) who will come into the race with only four starts in his career.

Several of the entrants have solid preparation that includes good performances in stakes company this year and last. They all happen to have top trainers as well: Any Given Saturday and Scat Daddy, both from the powerful Todd Pletcher barn; Great Hunter, trained by Doug O'Neill; and Nobiz Like Shobiz, trained by Barclay Tagg. Any of them would be a logical winner in a weak field.

But no 3-year-old has been pointed for the Saturday's race more thoughtfully than Street Sense. Trainer Carl Nafzger prepared Unbridled to win the Derby in 1990, and it is instructive to look at that colt's past performances. Unbridled raced respectably well at 2 and 3 but never did anything dazzling; he won the Florida Derby with a dismally slow figure. But then he exploded to win at Churchill Downs with one of the fastest and most impressive Derby performances ever.

Nafzger tipped his hand with Street Sense more than he did with Unbridled. The colt captured the BC Juvenile by 10 lengths, the biggest margin in the history of the race, and earned a speed figure of 108. He did take advantage of a rail-favoring bias at Churchill, so perhaps he is not quite as good as the margin of victory or the speed figure suggest, but this was nevertheless the best single performance by a member of his equine generation.

Nafzger has made it clear that his one objective this spring is to win the Kentucky Derby. Street Sense was surely not tuned for a maximum effort when he won his 3-year-old debut at Tampa Bay Downs, nor when he lost by a nose in a fluky Blue Grass at Keeneland. Nafzger undoubtedly has Street Sense primed to deliver his top effort, and if the colt even approaches the level of his Breeders' Cup performance he will win this Derby.

(c) 2007, The Washington Post