The difference between a zero score and a "nonscore" in AKC Hunting Tests is discussed on page 40 in "Regulations and Guidelines for AKC Hunting Tests for Retrievers." I'm not sure I can distinguish between the two. A zero is given when a dog is not able (failed) to exhibit an ability. The nonscore is given when the dog was not given the opportunity to attempt to show that he/she could complete the ability. How could a judge not give every dog a chance to try? Wouldn't every dog entered have a chance? And how do you calculate an "X" into the dog's score. I am sure I am missing something. Can anyone help?