I have tested him in a way, he doesn't have a mouth to tug. Maybe the dog respects me too much but he lacks biting power. The dog doesn't have great stamina and he is also not the most agile dog. I didn't have a decoy come out and try to attack me to see if he can do the job. BUt from simple observation on basic acitivities I don't think he qualifies for a good working. I also got his hips tested and they did not score so well, he is more of a great beast friend household pet who looks intimidating but that cannot excel if I needed him to lol We love him and that's all that matters, but he is no working dog and I have yet to see an American Bully built to the ABKC standard that can perform as well as a working mastiff and bullbreed cross. I love the American BUlly for what they are, great companions and great pets. If I need a dog to deter intruders and protect me from a wild beast I am not going to count on my dog to do that job lol