Automatic watches are extremely delicate. Unfortunately, not many people are aware of this. All they know is that it winds itself and that you need to have it on at all times.
It needs to be worn regularly as its gears are extremely sensitive. The mechanisms absorb the kinetic energy you produce, which powers its insides.
If you have an automatic watch, wearing it on your dominant hand is not advised due to this reason. This is because you’re always moving the hand around. Although some of the tasks you do will be easy, at other times they will be more rough, such as when playing tennis or doing carpentry, which creates an immense amount of kinetic energy.
Your automatic watch can’t withstand such energy. Over time, this will ruin its insides. No, it won’t break but this continuous, harsh energy flow will make the time less accurate. This is especially the case if the automatic watch is on the cheaper side as its parts aren’t that thorough.
Mechanical watches also function through gears and mechanisms. Although they’re not as sensitive as their automatic counterparts, if you have one on your dominant hand while you’re playing tennis, you’re flooding too much kinetic energy for it to bear. So, it will lose accuracy as well.