On which hand should men wear watches?

I saw a guy wearing his watch on his right hand and this got me thinking about this question. According to wrist watch specialists, there is no definitive answer. It just so happens that 89% of people are right handed and so they wear it on their less dominant hand which is the left one.
So the next time someone walks in and his watch on his left wrist, don't think that they are daft. It may be just that they are left-handed.