Whoever thought of this as a training method is a ding-dong. If you look at wolf behavior in the wild, the dog that is being submissive is not ever being forced. It is always on its own accord. Many people who do this method (that I've seen) force their dog on its back. In my opinion, this just makes for a very unconfident dog.
Ozzy rolls on his back for me and I rub my face in his fluff and give him tummy rubs.
Ozzy rolls on his back for me and I rub my face in his fluff and give him tummy rubs.