I don't fully understand the impact of watch position when it comes to accuracy. For one of my DOXAs, face up it will add nearly 10 seconds overnight (about 8 hours). However, top down it's nearly spot on, adding maybe a second over that same period. This works ok while wearing as well, since I wear my watch on my right hand, and the watch is then frequently top down. But I don't fully understand that. What's going on when the watch is top down that makes it so accurate? Or rather, when it's not top down, what's happening to make it so not accurate?