Hi Dan,
That may be what I'm seeing but I see a different dog at the dog park. Much more focused and driven to play ball. When he plays with Peyton he's fun, energetic and enthusiastic. Give him a command though and he moves very very slow. Try to teach him something and he almost shuts down. That';s the problem with a rescue, I don't know what this guy has been through. Whatever it was, Jax is what I would call a soft dog today.
Jax lacks confidence I think until he knows without a doubt, he is right. If that fear is freezing him and is getting in the way of him connecting the dots, I don't know. It's like there is an enthusiastic BC puppy inside him "somewhere" and I've seen it. It's just that I don't know how to bring it out.
You know that wild look all out dogs get in their eye when they are reallt amped. I'v
Have you tried making training just a fun, silly game, removing the seriousness from it?? High pitched voice, crazy praise, lots of play and ball as reward. Loose and fun, not strict, or demanding. Perhaps if you stand when training, and that makes him nervous, sit on the floor with him instead, get on a level that makes him comfortable. There is no need to be formal about it at this point if you are trying to build confidence in him.
And, your timing with the ball reward doesn't have to be exact. Just keeping practicing and using it as a reward and you'll get the hang of it.
I agree with Dan, you can train enthusiasm, but you can't change the drive of a dog if it's not genetically present. You can build enthusiasm for an object, toy, food, learning etc. but you can't really encourage a drive when there isn't one to encourage. You can, however, build upon a drive if it is genetically present in the dog, but has not yet surfaced due to new environment, fear, hesitation, stress etc. Give him a little more time to get comfortable, and you may see a different dog. Some dogs take a lot longer to become themselves in a new environment...days, weeks even months.
A game I use for control and focus, that really works well, is holding a coveted object in both hands (either food or toy) out to the side of you, and as soon as the dog looks at your face, instead of coveted object in hands, mark (yes, good etc.) and reward. Throw toy, or give the food. Eventually work up to longer periods that the dog has to hold the look at you, always with the reward for doing it. Start at just a second in a low distraction environment, and work up to a minute in small intervals. Then change to a more distracting environment, starting once again at a second, and work up. I've found that this helps to focus the dog (obviously), teaches some self control but at the same time maintains the enthusiasm for the coveted object/food with the dog learning to control his behaviour in order to receive the reward. You can eventually add a "look at me" command to utilize in different circumstances. I like eye contact, so I go for the direct stare and reward. However, if your dog is unsure about the eye contact, reward when he looks at your neck, your chin, your forehead etc. Don't ask for full direct eye contact if it's going to make him nervous. Work up to that.
Good luck, it can be disheartening to work with a dog who seems to have no motivation for training, but there is always something that the dog likes/wants, so use that to your advantage when training.