A Thoroughbred is a registered breed, while a Thoroughbred X (literally 'Thoroughbred cross') is a mixed breed with Thoroughbred blood present.
No, they just have to be a Thoroughbred
Life of a Thoroughbred was created in 1941.
If it was a short race Thoroughbred would have won but the type of Thoroughbred matters.
Irish Thoroughbred was created in 1981-01.
Irish Thoroughbred has 189 pages.
The duration of Life of a Thoroughbred is 660.0 seconds.
Ruffian was a thoroughbred racehorse.
Thoroughbred Retirement Foundation was created in 1982.
Its a Thoroughbred horse bred with another different breed!
Thoroughbred Breeder - series - was created in 1993.
No, the Thoroughbred series is a fictional series.