Unlike StackOverflow or any other technical Q&A sites where most answers can be described as "this answer works and is correct" or "this answer does not work and is wrong", answers in Japanese SE are more subjective and are hard to decide whether they are correct or not. I'm thinking of accepting the answer that has the best and most thorough explanation, but that by itself is subjective.
For example, for my question of What is the difference between 「はずがない」 and 「わけがない」?, I found both deceze's answer and hasen j's answer are excellent so I can't decide between accepting one of them. deceze's answer gives many examples to emphasize the difference while hasen j's answer is compact yet immediately makes sense.
So, in general, how to choose which answer to accept? Let's just say that the number of upvotes should not be the primary reason to accept an answer. Or should it?