Teaching your puppy a middle, or safe position, helps them learn to come into a secure space between your legs where they can feel calm and protected. This can also be a really fun exercise to practise, and many puppies genuinely enjoy it. As your puppy becomes more confident, it can even be developed into a playful recall-style game, encouraging them to run back into position with enthusiasm.
Start slowly, each step at a time, and only progress once your puppy is confident and understanding the criteria of each step.