Many colors, color patterns, and combinations of colors are acceptable to the ADBA, except that both the ADBA and UKC do not recognize merle coloring. The AKC stud book was opened a few more times until it was last closed around the 1970s. In 1972 the AKC changed the name of the breed to American Staffordshire Terrier as it already intended to recognize the British Staffordshire Bull Terrier as a separate breed in subsequent years.Today a discussion persists whether the American Pit Bull Terrier and the American Staffordshire Terrier are two separate breeds or still the same breed. The fact is that Pit Bull and AmStaff breeders have distanced themselves from each other by pursuing different goals over than 30 years, producing dogs with physical and temperament differences. Since 2015, the American Dog Breeders Association (ADBA), which has registered the American Pit Bull Terrier since 1909, considers the American Staffordshire Terrier to be a different separated breed.