SELECTIVE CONDITIONS AT THE FLAT TRACK
This graph shows the “selective conditions” of modern flat-track racing in different world regions. Four-mile heat-races became extinct 150 years ago. There are still a tiny number of Thoroughbred races that require horses to run more than two miles; all of these are in Great Britain. Even races of between 12 and 16 furlongs, at the upper end of “classic distances,” are now relatively rare. Races of one mile are commonest, but “sprints” of less than one mile are a close second in popularity worldwide and are the most popular in the United States, where races of six or eight furlongs comprise the overwhelming majority of all races. The Australian pattern parallels that in the United States whereas the European pattern is similar to the British.