Everything I write is of course my own opinion, the same goes for whatever you read on any history book and even physics.

Warning: Fallacy of gray detected.

The difference is in ability to infer facts about the world from assertions about facts about the world. Assertions differ greatly in their convincing power. An argument is made strong by either being explanatory, drawing your attention to a way of making your own conclusions, or by having its own truth and relevance as a powerful explanation for having been made, while for a weak argument other reasons are not ruled out.