When Strategic Maneuver won the Spinaway Stakes (G1) at Saratoga Race Course in August 1993, she did more than capture a prestigious stakes race for her connections. The Cryptoclearance filly also ushered in a new era in Thoroughbred breeding as the first stakes winner inbred to the legendary Mr. Prospector.

Over the past eight years, an additional 21 unrestricted stakes winners inbred to Mr. Prospector within four generations have appeared. This year, Invisible Ink (3x3 to Mr. Prospector) ran second in the Kentucky Derby (G1), and sale catalogs have been full of horses inbred to the late Claiborne Farm stallion.

What meaning can be attached to the fact that, as of July 1, 2001, there have been 22 stakes winners that are inbred to Mr. Prospector? (For this study, stakes winners are winners of unrestricted stakes races worth at least $25,000 and run in North America and Europe; inbreeding indicates duplications within four generations.)

Before the number 22 can be evaluated, it must be put into context-some sort of par value must be found. One way of providing context is to look at statistics on inbreeding from two other prominent stallions, with an eye on subsequent changes in the North American stakes program.

Mr. Prospector's first crop was born 25 years ago, and the search for a par value begins by looking at the status of inbreeding to Northern Dancer and Bold Ruler 25 years after their first crops were foaled.

In terms of the quality of his male-line descendants and consequently the sheer quantity of different ancestors in their pedigrees, Northern Dancer is perhaps the most accurate measuring stick. As with Mr. Prospector, Northern Dancer's effect on the breed has been enormous, and the number of stakes winners inbred to Northern Dancer is now more than 500.

Ten years ago, however, when Northern Dancer's first crop was 25, the story was different. On July 1, 1991, 15 stakes winners carried multiple strains of Northern Dancer; by year's end, another nine had emerged for a total of 24 for the year.

The first stakes winner inbred to Northern Dancer appeared in 1985, when members of the stallion's first crop were 19 years old. An additional single stakes winner appeared in 1986 and '87, followed by three in '88 and two in '89. The number has increased every year since, with more than 90 such winners in 2000 and more than 40 to date this year.

It is also instructive to look at the development of Bold Ruler inbreeding.

Inbreeding to Bold Ruler also has been plentiful, and there are now more than 300 stakes winners inbred to the eight-time champion sire. Also, like Northern Dancer inbreeding, the oak was once an acorn. On July 1, 1985, members of Bold Ruler's first crop had reached age 25, and there were 13 stakes winners carrying multiple strains. Another four were added during the second half of the year for a total of 17. The first stakes winner inbred to Bold Ruler appeared in 1982, when his first crop was 22 years old.

Fappiano and females

By comparison, Strategic Maneuver's win in the Spinaway came when Mr. Prospector's first crop was age 17. She was the lone inbred stakes winner in the club until Fuzzy Me appeared in 1995 and Mon Cherie in '96. Four more appeared in '97 and '98, seven were added in '99, five in 2000, and three thus far in '01.

It should come as no surprise that half of the stakes winners inbred to Mr. Prospector involve a cross of Fappiano. Winner of the 1981 Metropolitan Handicap (G1), Fappiano was a member of Mr. Prospector's second crop in 1977, and his branch of the sire line has been the most influential through such sons as Unbridled, Cryptoclearance, and Quiet American. In fact, 17-year-old Cryptoclearance, Fappiano's eldest Kentucky-based son, has sired three of the 22 inbreds and is the broodmare sire of another. We see a similar scenario with Northern Dancer's early, prolific son Nijinsky II, who is present in 14 of the first 24 Northern Dancer inbred stakes winners.

Females have played a large role in Mr. Prospector inbreeding as well, with ten of the inbreds showing at least one cross through a daughter of Mr. Prospector. Two mares appear twice: Silver Deputy's dam, Silver Valley; and 1982 champion sprinter Gold Beauty, dam of the Seattle Slew stallion Gold Legend (among others). Sheer Sable is the only stakes winner with two female strains, and J W Jet is the only stakes winner with three crosses. Meanwhile, only four of the 16 (five of the 25 by year's end) early Northern Dancer inbreds involved a female cross.

As further testament to Mr. Prospector's prowess as a broodmare sire, eight of the inbreds also show a cross of the stallion in the female family of the dam. Of those, seven show the son of Raise a Native as either the broodmare or paternal great-grandsire of the dam.

Factoring changes

The drastic increase in the number of stakes races run over the past two decades also must be addressed when evaluating inbreeding to the three stallions. From 1980-'85, when Bold Ruler inbreeding began to emerge, there were, on average, approximately 1,188 unrestricted stakes races run in North America and Europe. From 1985-'90, about the time we began to see a significant number of Northern Dancer inbreds, the average number of unrestricted races was roughly 1,890. Over the past six years, there have been around 2,200 stakes races run annually. This is most likely part of the reason why the first Bold Ruler inbred stakes winner did not appear until his first crop was age 22, while Mr. Prospector's first inbred stakes winner showed up when his first foals were 17.

The rise in the number of stakes races has been a purely North American phenomenon. The number of black-type events has remained virtually the same in Europe since 1985, while the total stakes races in the United States and Canada have increased nearly 50%. This is relevant because the vast majority of Mr. Prospector blood is in North America. The increase in stakes run on this continent has surely aided in generating the total number of stakes winners inbred to Mr. Prospector that we now see.

Meanwhile, Northern Dancer's influence is even greater in the breeding centers of Europe. In fact, 14 of the 24 early Northern Dancer inbreds won stakes on European racecourses, while the same is true with only two of the 22 Mr. Prospectors thus far.

So, now we have a little better idea of what to look for. Thirteen stakes winners were inbred to Bold Ruler halfway through 1985, 25 years after his first crop was born in an era when about 1,100 stakes were run each year. Halfway through '91, there were 16 stakes winners inbred to Northern Dancer at a time when close to 1,900 stakes were run annually. With mainly a North American increase, there are now over 2,200 stakes races per year and 22 stakes winners inbred to Mr. Prospector.

In light of the enormous increase in North American stakes races, the 22 Mr. Prospector inbred stakes winners is a number that turns out to be a little weak compared with his predecessors. The dramatic lack of quality of those 22 stakes winners-while a concern in itself-provides further evidence that, were it not for more stakes, there would be far fewer stakes winners carrying Mr. Prospector inbreeding.

Only six of the 22 Mr. Prospector inbred stakes winners are graded winners (27%) and only two (9%) are Grade 1 winners, with last year's Cigar Mile Handicap (G1) winner, El Corredor, joining Strategic Maneuver at that level. A look at the histories of the 25 nongraded stakes races won by the 22 Mr. Prospector inbreds shows that 18 (82%) were inaugurated within the past 15 years. In other words, races the Mr. Prospector inbreds are winning are precisely the ones created in the boom of stakes races over the past two decades.

This lack of graded winners is especially disconcerting when compared to the early Bold Ruler and Northern Dancer i