Given a player with an ELO rating of 1200, and another with an ELO rating of 2100, how would you calculate an appropriate handicap?
I know this can vary a lot depending on styles of play. I'm not looking for a globally correct answer. Just a rough rule-of-thumb.
As I said, I'm not asking for an exact science, but a rule of thumb. This question and its answers are discussing an exact method and how it compares to Go, which is not what I'm asking about.