A plaque on this picture suggests that the event shown is Cosmo beating Gimcrack over the Beacon Course at Newmarket, 1 April 1769. While such a match did indeed take place, the identification appears erroneous for several reasons. Cosmo was a brown, while the leading horse in this picture is bay, and the jockey's colours fit neither of Cosmo's two owners: Lord Rockingham and Sir Charles Bunbury. Gimcrack was originally an iron grey and even in old age had a good deal of black in his legs. Stylistically, it is likely that the picture dates from circa 1730 rather than 1769 or later.
The colours on the grey in fact look to be those of the 2nd Duke of Devonshire, while the jockey on the 'winner' could be riding for the Duke of Bolton. Although no such match (bay versus grey, with these owners) is documented, it is quite possible that, for an imaginary scene, Burford would choose to show horses riding in the colours of the two major owners of the period. The composition bears a very significant debt to Wootton, but the artist has also incorporated elements which are influenced by both John Vanderbank and James Seymour.