The ‘rule of thirds’ is often quoted as a compositional rule that photographers should follow, and by ‘judges’ who really should know better if they are going to talk about composition!
It’s just a grossly over-simplified version of two other guidelines that artists have used as a starting point for centuries, and the original guidelines (not rules!) are more informative and not that much more difficult to put into practice.
Of course, being a lazy photographer, I’ve not bothered to put together a long post with examples … especially since someone else has already done it! … go visit the lazy rule of thirds by Jake Garn!

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