Pretty Polly, was an outstanding Irish bred Thoroughbred racehorse and an outstanding broodmare. She won fifteen consecutive races and was only the fifth filly to win the British Fillies Triple Crown since its inception in 1814.
Precipitation was an influential British bred Thoroughbred stallion who is found in the pedigrees of many racehorses and sport horses today. He alone is responsible for maintaining the Matchem sireline, through Sheshoon, except for the American Fair Play branch.
Pocahontas (1837–1870) was an English Thoroughbred racehorse and the dam of three sires who had a great influence on the breed. Although mares are not generally considered to be as influential as sires, Thoroughbred Heritage refers to Pocahontas as "one of the most influential Thoroughbreds of all time, male or female."
Glencoe (1831–1857) was a British bred Thoroughbred racehorse, who won the 2,000 Guineas Stakes and the Ascot Gold Cup. He was one of the earliest Thoroughbred stallions imported into the United States and was a top broodmare sire there. Several outstanding sons of Lexington were out of Glencoe mares, including Asteroid, Kentucky and Norfolk.
Buckpasser (1963–1978) was an American-bred Thoroughbred racehorse that won 9 of his 11 race starts for international record winnings for a two-year-old of $586,090. He was a leading broodmare sire in 1983, 1984, and 1989.
La Troienne (1926–1954) was one of the most famous and influential Thoroughbred broodmares in twentieth century America. She produced 10 winners including two Hall of Fame inductees while at stud, while her daughters in turn produced many notable offspring. In 2000, pedigree expert Janeen Oliver designated her as the taproot of family 1-x, a designation that was implemented by the Pedigree Online Thoroughbred Database in 2003. Recent matrilineal descendants include 2003 Horse of the Year Mineshaft and Kentucky Derby winners Smarty Jones (2004) and Super Saver (2010).
Bayardo was a British bred Thoroughbred racehorse with an impressive record, both on the racecourse and at stud, where he was a leading sire.
Mahubah (1910–1931) was an American bred Thoroughbred racemare that was noted for producing the outstanding racehorse, Man o' War.
Gainsborough (1915–1945) was a British bred Thoroughbred racehorse who won the English Triple Crown in 1918 and became a superior sire.
Crepello (1954–1974) was a British-bred Thoroughbred racehorse which won England's most prestigious race, the Derby in 1957 and was later a Leading sire in Great Britain & Ireland.
Somethingroyal was an American Thoroughbred racehorse best known as the dam of U.S. Triple Crown champion and Hall of Fame inductee Secretariat. She also produced three other stakes winners and was named the 1973 Kentucky Broodmare of the Year.
Hurry On was an undefeated British Thoroughbred racehorse and sire that revived the Matchem sire line. English trainer Fred Darling called Hurry On the best horse he ever trained.
Thoroughbred breeding theories are used by horse breeders in an attempt to arrange matings that produce progeny successful in horse racing. Bloodstock experts also rely on these theories when purchasing young horses or breeding stock. A basic understanding of these theories can also help the racing public understand a horse's theoretical genetic potential. The breeding theories stem from the belief that careful analysis of bloodlines can lend predictability to breeding outcomes. A well-designed mating increases the probability of the offspring's success, although many other factors also come into play.
Bois Roussel (1935–1955) was a French-bred Thoroughbred champion racehorse and a leading broodmare sire. He won the 1938 Epsom Derby on his second racecourse appearance.
Plucky Liege (1912–1937) was a British Thoroughbred racemare who produced eleven winners, including an Epsom Derby winner at the age of twenty-three and three British Classic race winners. The performances of these horses led to her becoming one of the most important broodmares of the 20th century.
Crucifix (1837–1857) was an undefeated, Classic Race winning, British-bred Thoroughbred racemare. She was also the dam of three sires who had a great influence on the breed.
Eleanor was a British Thoroughbred racehorse bred by Charles Bunbury and was the first female horse to win The Derby. Eleanor also won the 1801 Epsom Oaks among many other races before retiring from racing at age eight to become a broodmare for Bunbury. She produced the stallion Muley, which in turn sired the mare Marpessa and the influential stallion Leviathan which was exported to the United States in the early nineteenth century. Through the produce of her daughter Active, Eleanor is present in the pedigrees of 19th-century American Standardbred racehorses.
Cobweb (1821–1848) was an undefeated British Thoroughbred racehorse and who won two British Classic Races as a three-year-old and went on to become a highly successful broodmare. Cobweb's racing career consisted of three competitive races in the early part of 1824. After winning on her debut she claimed a second prize when her opponents were withdrawn by their owners. She then won the 1000 Guineas at Newmarket Racecourse and the Oaks Stakes at Epsom Downs Racecourse before being retired to stud.
Sicarelle was a French Thoroughbred racehorse and broodmare. Her racing career comprised six races in six months between April and October 1956. After wins in the Prix Perdita and Prix des Lilas she was sent to England and won the Epsom Oaks. She was unplaced in her next three races before being retired from racing. She had some success as a broodmare in the United States.
Australian was a British-bred Thoroughbred racehorse and sire. He was exported to the United States where he had modest success as a racehorse but became a very successful and influential breeding stallion.
