His dam was Armful, whose sire was Belmont Stakes winner Chance Shot and whose grandsire was the great Fair Play.
Since he was also practically untrainable, his trainer, Ben A. Jones, sent him back to Calumet Farm to be gelded and turned out to grow up.
On April 20, 1946, under jockey Douglas Dodson Armed broke the track record for a mile and a sixteenth on dirt with a winning time of 1:43 1/5 in the Philadelphia Handicap at the Havre de Grace Racetrack.
Triple Crown champion Assault in a match race at Belmont Park and set a track record of 2:01-3/5 for one and one-quarter miles while winning the Widener Handicap and carrying 129 pounds.
In the Horse of the Year poll conducted by Turf and Sport Digest magazine, he received 151 of a possible 173 votes to win the title from Citation, Stymie, Bewitch and Assault.