I'm a believer that the offleash bond starts with young puppyhood. At least that's the only way I know. I don't know how to create that with an older dog.
I'm getting ready to test that theory soon with a guy that's been with me a few months. I think I have the control and bond with him now that it can be done -- and more importantly -- that *I* have the faith and belief and confidence in it.
Dogs do pick up on these things. My boyfriend cannot do anything offleash with any of the dogs. He gets so nervous and tries to call them back in such a frantic type of way.
Classes can only help, but I honestly and deeply believe it is about the bond with the dog. Sure he will want to run and explore, but is he keeping track of you, too? Do you have a safe area to try it out? Are you going to be in the right frame of mind, ie, not be all frantic and scared if the dog gets however many feet away?
I just walk. They just follow. They may veer off to sniff, to do whatever, but I honestly don't worry about it. Granted, I'm in a safe area. Large area, fenced area, whatever... but once I'm totally secure in the surroundings, I let them be dogs and they've not disappointed me.
Your feelings have a lot to do with it, but only you know your dog. If the dog has never known offleash freedom, he may bolt.
Don't panic. Again, be sure it is a safe environment, and let him go. If your bond is good with the dog, after the initial freedom, the dog will want to know where you are. Will sniff you out. Will check in with you before running off again.
Just again, be sure it is a really safe environment. If you can't assure that, start with a super long lead.