The award originated in 1936 when the Daily Racing Form (DRF) began naming an annual champion.
In the same year, the Baltimore-based Turf and Sports Digest magazine instituted a similar award.
Starting in 1950, the Thoroughbred Racing Associations (TRA) began naming its own champion.
Whenever there were different champions named, the horses are listed side by side with the one chosen as champion by the Daily Racing Form noted with the letters (DRF), the one chosen by the Thoroughbred Racing Associations by the letters (TRA) and the one chosen by Turf and Sports Digest by the letters (TSD).
Champions from 1886 through 1935 were selected retrospectively by a panel of experts as published by The Blood-Horse magazine.