In conventional gundog training, force fetch or retrieve training is usually taught early, along with other obedience commands. People often ask why I instead, add a natural retrieve as the last step in training.
Retrieve, in my method, is done last, after a dog understands that steadiness leads to success and that we can help (the building of trust). In a dogs mind, retrieving, as an obedience command, is unnatural. The fact that you’re going to force the dog to bring his reward to you so you can steal it from him makes you by definition, “untrustworthy” in his eyes. That’s why it takes pressure and lots of repetition. Early retrieve work, before building trust, can lead to problems including a lack of desire due to adding unnecessary stress. In my method, because we add the retrieve AFTER building trust, the dogs see it not as an obedience command, but as naturally sharing the kill.