[Rikki]

The higher the power on the mainspring the more stable the amplitude and the more degree of arc which is what amplitude is. As the balance spins to its furthest degree of arc and engages the pallet fork it moves the rest of the gears. At full power and amplitude it is the longest time between beats, as the power decreases the amplitude also decreases causing the balance to engage the pallet for sooner causing the watch to speed up slightly. Rolex watches are tested at full power and again after 24 hours and the timing is averaged out. Hope that explains a little bit about what goes into timing also 5 to 6 position timing to get a better timing average. Rik