As a dog walker that's just going off years of experience without any formal certs or anything fancy- I feel like it's more about location/proximity than about the exact position Like, don't reach down to the top of the dog's head from above. You're looming over them, and kinda scary in this position. Aim for chin scritches rather than head pats. Disclaimer: just based on my experience and the training videos I've watched, I don't claim to be an expert 😅