American Staffordshire Terrier Types
Terrier Type :
Showing a strong relationship to the terrier in the background, this body type is quick, agile, tight, sometimes leggier, lighter boned, carrying less muscle mass. This type is often very stylish and elegant. This type should not be preferred over the others, as it can be quickly exaggerated, losing the muscle mass that is desirable in the breed.
Moderate Type :
The perfect blending of the bull and terrier background, with strength and musculature of the bulldog, and the grace and agility of the terrier. If any type should be preferred, this would be the one.
Bully Type :
Characterized by heavier bone and more mass. This type falls more toward the bulldog ancestry. Somewhat shorter on leg and heavier moving, they also have more tendency toward looser, thicker skin.
Reference : Staffordshire Terrier Club of America Inc.