[3] She was from the seventh crop of foals sired by Big Game the best British colt of his generation, whose wins included the 2000 Guineas and the Champion Stakes.
Traffic Light's dam Point Duty (foaled 1926) was an influential broodmare whose other descendants have included Mannamead, Sodium, Madelia, Black Caviar and Solow.
Later that month she took on male opposition in the White Rose Stakes at Hurst Park and recorded her first success as she won by a neck from the colt Fellermelad.
[3] On 4 June Ambiguity, partnered by the 18-year-old apprentice jockey Joe Mercer, started at odds of 18/1 in a 21-runner field for the 175th running of the Oaks over one and a half miles at Epsom Racecourse.
[5] After tracking the leaders, Ambiguity went to the front a furlong from the finish and stayed on strongly to win by a length from Kerkeb, with Noemi taking third ahead of Happy Laughter.