At any organized pit fight in which two dogs are really going at each other wholeheartedly, one can observe the owner of each dog changing his position at pit-side in order to be in sight of his dog at all times.
When Vick's property in Virginia was raided, 54 pit bull terriers were found, some with apparent dog fighting injuries, as well as training equipment like a treadmill and a stick used to pry open dogs' jaws.