How can a self-winding mechanical watch be effectively wound?

A self-winding mechanical watch is designed to be wound automatically by the movement of the wearer's wrist. This is accomplished through a component called the rotor, which is a semi-circular piece of metal that swings as the wrist moves. The motion of the rotor is transmitted to the gear train, which ultimately winds the mainspring, storing energy and allowing the watch to run without the need for manual winding or an external power source.

This feature differentiates self-winding watches from manual ones, which require the wearer to turn the crown to wind the mainspring. The reliance on kinetic energy from the wearer's movements makes self-winding watches convenient, as they are less likely to stop running as long as they are worn regularly. Therefore, the correct understanding of how a self-winding mechanical watch is wound lies in recognizing the role of the rotor and the automatic mechanism it creates through motion.