This is a serious question though, and I don't mean around your neck vs. your ankle vs. your cat. I mean above or below your wrist knob, whatever that's called. Cue giggling. My FitBit Charge HR recommends, for best heart rate monitoring, to fit it two finger widths above the bone. Because my arm is tapered, like most arms, I find that virtually impossible without having it slip, but it is comfortably snug and not too tight about 1cm above the bone. When I went for my try on at Apple, the employee who helped me said the recommended place is pretty much exactly where I was wearing my FitBit. I don't know if this is the official recommendation from Apple or not, but this guy was great and seemed genuinely very knowledgeable. Now, I see a LOT of pictures where the Apple Watch is either pressed right up against the base of the hand (to the point I wonder if the crown gets turned or pressed accidentally), or sometimes right over the wrist bone knob. I wonder then, if the variability I'm seeing in reports of reliability of heart monitoring or movement tracking is because of watch placement. Has anyone experimented with this?