Every year, a new set of South American-bred imported runners makes headlines in American racing, usually in California and usually in the barns of trainers Richard Mandella or Ron McAnally. Each new graded stakes winner named with a Spanish or Portuguese accent sends pedigree enthusiasts scrambling to their stud books, trying to figure out who these horses are and why they are so good.

This year's crop of South American imports appears just as tough as ever, headed by Riboletta (Brz), trained by former McAnally assistant Eduardo Inda. Riboletta is clearly the best older mare in the West and one of the three best in the country.

Imported to the United States last year after winning the Grande Premio Diana (Brazilian Oaks) (Brz-G1) in her native land, Riboletta won only 1-of-6 starts in 1999 when trained by Bob Baffert. She has blossomed this year under Inda's tutelage after owner Aaron Jones transferred the five-year-old mare to his stable late last year.

Riboletta was sired by Roi Normand-an unfamiliar name to American ears with very familiar antecedents-out of Joy Valley, by Ghadeer, an even less-familiar name. Roi Normand, despite his French name (translated as King of Normandy or Norman King), was bred in America by the de Moussac family, owners of Haras de Mezeray in Normandy.

By two-time leading American sire Exclusive Native, more famous as the sire of Affirmed and Genuine Risk, Roi Normand placed in two listed races in France before his importation to the U.S. at five in 1988. He won two graded races that year, the Sunset Handicap (G1) at Hollywood Park on turf and the Ark-La-Tex Handicap (G3) on dirt at Louisiana Downs.

Despite that versatility, there was little demand for a long-winded son of Exclusive Native at stud in America in 1990, and Roi Normand was sold for stud duty to Jose Carlos F. Pires's Haras Santa Ana do Rio Grande in Brazil. A very well-bred horse out of group winner Luth de Saron (Fr), by Luthier, and half brother to group-graded winners Trampoli and Luth Dancer, Roi Normand was an instant success in Brazil. His first crop included multiple Group 1 winner Magnum Opus, and to date he has sired at least 20 stakes winners, though Jockey Club Information Systems records are incomplete for Brazil.

That number includes 14 group or graded stakes winners, headed by Riboletta's full brother Super Power, champion two-year-old in Brazil and winner of the Brazilian Triple Crown last year. He will soon be in training in Kentucky with W. Elliott Walden.

Ghadeer, sire of their dam Joy Valley, was a son of Lyphard who was England's top- priced yearling in 1979. Ghadeer won only one Group 3 race in Italy but has led the Brazilian sire list on several occasions.

Riboletta's and Super Power's first two dams are both Brazilian stakes winners, while third dam My Valley, by *Val de Loir, was imported to Brazil in utero from France.

Brazilian number two

Mandella has enjoyed tremendous success in recent years with Brazilian-breds Siphon (Brz), Sandpit (Brz), and Romarin (Brz), and he won the Mervyn LeRoy Handicap (G2) on May 13 with Out of Mind (Brz). Sestero, the sire of Out of Mind, is an even more unfamiliar name to Americans, and with good reason.

Bred in Brazil, Sestero broke down after placing in two stakes as a two-year-old in Rio de Janeiro, forcing his retirement to stud. Sestero was one of many good colts sired in Brazil by Executioner, one of the best sons of The Axe II.

Winner of the 1971 Flamingo Stakes and 1972 Metropolitan Handicap, Executioner was one of the best runners of his crop but a miserable failure as a sire in the U.S. In Brazil, however, he was leading sire in 1987, and his offspring include champion California Hope (Brz) and classic winners Grimaldi, Steff Graf (Brz), Vamare, and Interalliee.

Sestero's dam, Serencia, was by Great Heron, a Darby Dan-bred, Irish-raced son of *Sea-Bird and was out of a mare from a good English family. Out of Mind's female family has been in Brazil for many generations, but each of the sires along the female line is European-bred or has an entirely European pedigree. Out of Mind's family has been a consistent source of Brazilian stakes winners since the importation of his sixth dam Djerba in the 1950s. Bred by Marcel Boussac, Djerba (by Djebel) won the prestigious Cheveley Park Stakes at Newmarket in 1946 as one of the first vanguards of Boussac's postwar French invasion.

Mandella also trains Big Ten (Chi), the best two-year-old of his year in Chile. Big Ten won the Californian Stakes (G2) on June 11 and recently ran second in the Longacres Mile Handicap (G3).

Big Ten's pedigree, by Barkerville out of Chispita, by Chairman Walker, is a bit more recognizable to American breeders. Although his sire's name will not ring many loud bells, Barkerville is extremely well bred, by Mr. Prospector out of Euryanthe, by Nijinsky II. He won the 1992 Fayette Stakes (G2) and 1993 Tropical Park Handicap (G3) before his export for stud duty to Chile in 1993.

He scored an immediate success standing at Haras Carioca, siring at least four group winners in his first three crops. That motivated his reimportation to Kentucky, where he now stands for a $5,000 fee at Wafare Farm.

Although Chilean-bred, Big Ten's dam, Chispita, has an American pedigree. Her sire, Chairman Walker, is by Buckpasser out of Secretariat's half sister Swansea, and her dam, Fillette, is an American-bred by *Roi Dagobert out of a Bold Ruler mare.

American transfusion

Big Ten's pedigree is emblematic of the transfusion of the best American blood that has suffused the pedigrees of South American horses over the last 20 years. Formerly almost exclusively patrons of English and French exports, South American breeders were quick to read the currents of international bloodlines as descendants of Northern Dancer and Mr. Prospector began to dominate European headlines two decades ago.

Another prime example of this phenomenon is Arlington Million Stakes (G1) pacesetter Asidero (Arg), who seems certain to add his name to the list of Argentine-bred U.S. graded winners trained by McAnally in the near future.

Asidero's sire, Fadeyev, was bred in Kentucky in 1991 by Sheikh Mohammed bin Rashid al Maktoum's Darley Stud Management. Fadeyev is by Nureyev out of Skating (Ire), by Mill Reef.

Fadeyev lived up to that illustrious pedigree to an extent by winning the 1993 Prix Thomas Bryon (Fr-G3) and '94 Prix de Fontainebleau (Fr-G3), but he failed in more prestigious races. That was not good enough to win a place in Sheikh Mohammed's breeding plans, and Fadeyev was exported to Argentina in 1995, where he stands at Haras de la Pomme.

Asidero, from Fadeyev's first crop, was easily the best three-year-old in Argentina last year, winning six races in succession, including three of the four tiers of the Argentine Quadruple Crown, the Polla de Potrillos (Argentine Two Thousand Guineas) (Arg-G1), Premio Jockey Club (Arg-G1), and Premio Carlos Pellegrini (Arg-G1).

Asidero's dam, Lady Aspasia, by Tunerup, was bred in America but placed in stakes in Argentina. Her grandam, *Aspasia II, by In the Gloaming, was a top Argentine filly who placed in the 1970 Knickerbocker Handicap in the U.S.

*Aspasia II descends from one of the best female families in the Argentine Stud Book.

At one time, the pedigrees of South American imports invariably represented outcrosses of unfamiliar names only distantly related to the best American strains. With American bloodlines now pervading international pedigrees, that is no longer true.

While that may make it easier for South American-breds to integrate their genes into the American tapestry, it represents just one more step in the continuing homogenization of the Thoroughbred.

Something is gained by that process, but something is lost as well: diversity of aptitude and pedigree.