Formidable was a "robust, attractive, strong-quartered"[2] bay horse with two white socks (on his right front and left hind leg) bred in Kentucky by Ralph C. Wilson, Jr. His sire Forli was a champion in his native Argentina before becoming a successful breeding stallion in the United States where the best of his offspring included Thatch and Forego.
[5] Nine days after his win at York, Formidable was moved up in class and started the 13/8 favourite for the Group Two Mill Reef at Newbury Racecourse.
[5] Formidable sustained a pulled muscle in his hindquarters in the early part of 1978 and had not fully recovered when he ran unplaced behind Roland Gardens in the 2000 Guineas.
In June he was moved up in distance to contest the 199th running of The Derby and ran well for a long way before fading in the final furlong and finishing unplaced behind Shirley Heights.
He was brought back in distance for the St James's Palace Stakes at Royal Ascot later in the month and finished third behind Jaazeiro and Persian Bold.
On his only subsequent appearance that year, the colt was sent to France for the Prix du Moulin at Longchamp Racecourse on 24 September but made no impact, finishing ninth of ten behind Sanedtki.
[2] In the early part of 1979 Formidable was dropped in class and had his first successes since his two-year-old season as he recorded easy wins in minor events over one mile at Wolverhampton and Brighton.
In May he defeated Roland Gardens by a length in the Cold Shield Windows Trophy over seven furlongs at Haydock Park Racecourse, but appeared to be a rather lucky winner as the runner-up had struggled to obtain a clear run in the closing stages.
[11] There was no International Classification of European two-year-olds in 1977: the official handicappers of Britain, Ireland and France compiled separate rankings for horses which competed in those countries.