Why is it that sometimes the last rank listed in a game history table is not the same as the person’s current rank?
The only reason I can think of is if the game-history rank is locked in at the moment of the game finishing and rank being calculated (makes sense) and the person’s actual rank later changes due to opponent rank changing and causing recalculation of the person’s actual rank.
That totally explains it. I guess it also mean that therefore if you see a person who’s display rank is different to their last game rank, it means that last game caused them to rank.
Out of curiosity, how do we know this is the case? Isn’t this back end code?
You simply have to compare the ratings in the game history with the ratings in the rating history. You will find the ratings in the game history to be one game behind the rating history.