(Dogs to Kevin)
A system that I go with when doing off leash hiking with my dog is if he comes back on his own without me asking, he gets 1 reward. If he comes back when I call and it was quickly, I will give two rewards. If he comes back when I call when there is a huge distraction I give a ton of rewards. I don't even think I count. Just one after another with plenty of sincere enthusiasm. Most importantly, after he comes when called and gets his reward, I release him to go off and run again. This turns it into a double reward system. Try this out, you should have a lot of success with it. Definitely use a long leash at first until you trust that your dog will come back every time you call.