Tibthorpe's appearance and performance led to suspicions of foul play. During this period there were several cases of four-year-old horses having their identities faked and running in races, notably the British Classics, which were confined to three-year-olds. Tibthorpe's win at Newmarket was only confirmed after an examination of his teeth, demanded by Tom Tulloch's owner Lord Maidstone, which established that he was indeed a three-year-old colt. The Yorkshire-trained horse was promoted to second favourite for the Derby, and Scott renamed him after Sir Tatton Sykes, 4th Baronet a notable breeder of Thoroughbreds based at Sledmere. At Epsom on 27 May, Sir Tatton Sykes started at odds of 10/1 for the Derby in a field of twenty-seven runners.
Tibthorpe's appearance and performance led to suspicions of foul play. During this period there were several cases of four-year-old horses having their identities faked and running in races, notably the British Classics, which were confined to young adult ages. Tibthorpe's win at Newmarket was only confirmed after an examination of his teeth, demanded by Tom Tulloch's owner Lord Maidstone, which established that he was indeed a three-year-old colt. The Yorkshire-trained horse was promoted to second favourite for the Derby, and Scott renamed him after Sir Tatton Sykes, 4th Baronet a notable breeder of Thoroughbreds based at Sledmere. At Epsom on 27 May, Sir Tatton Sykes started at odds of 10/1 for the Derby in a field of twenty-seven runners.

