In academic writing, a theory is a well-substantiated explanation of some aspect of the natural world that is acquired through the scientific method, and incorporates facts, laws, inferences, and tested hypotheses.
The phrase “my best theory” is often used to introduce a personal view or opinion on a particular topic. It can be seen as a way of saying “this is my current understanding of the situation, but I am open to new information that may change my mind.” The word “single” in this context suggests that the theory is focused on a specific aspect or issue.
