I found a funny behavior. When I post an answer, it isn't always last, despite earlier answers before me. Is the sorting not chronological? Is reputation a part of the ordering?
Answers are sorted according to the tab you've selected: Activity, Oldest, Votes.
When answers are ordered by votes, higher voted answers appear at the top of the list. Answers with the same number of votes are randomized. The accepted answer appears at the top of the list as long as it wasn't written by the person who asked the question (OP). If the accepted answer was written by the OP, then it is sorted according to its votes.
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