If someone new were to take over Amazing Spider-Man, how many back issues would they be expected to read? I know that Hickman read all of FF as prep for his run, same with Bendis for Avengers and X-Men, but Spidey has had so many titles for so long that it probably doubles most characters' history.
As many as they needed to have read in order to write the character effectively. So that could be 500 or it could be 1.