After I read through the advice here, I went and talked to a trainer and then decided to work with Oliver for a few more sessions. I used a 25 foot rope and choke collar and pretended I was a drill sergeant. I was very firm with him. I am happy to report that the last few days, he comes right to me even without a rope on and even with a bumper that I've tossed as far as I can, he comes directly back. However, I think I can read his mind and it seems like he might be tempted to run around and play keep away. So far, though, so good. He is not the natural that my Blazer was but Oliver does try his best to please. Thanks for the help.