When a dog has passed the health screening and temperament screening with flying colors, that is only the beginning. Sometimes the opposite occurs. For example, a dog with a very sensitive nature may be too intimidated by someone with a boisterous or belligerent personality and loud booming voice to perform well. Yet he might do well with a soft spoken handler who gently encourages him with praise.
Some handlers can easily adjust their handling style to suit a dog's personality.
Others seem inflexible and require a very confident dog who tolerates human foibles with good natured stoicism. One of the most important factors in successful match-making is a dog's energy level. Someone with a busy lifestyle full of extracurricular activities outside the home won't find a sedate laid back couch potato to be a good choice for their particular situation. Someone who leads a quiet sedentary lifestyle won't get along well with a high energy dog who needs plenty of work and stimulation to keep him content and out of trouble. On occasion, the dog's companionship potential can make or break a partnership.