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.
This page presents a table of odds for rough ELO differences, used for games between a human and computer. Since my proposed difference is 900 points, this most closely matches the odds of removing a knight or two pawns.
A difference of 900 points at the level you showed (2400 vs 3300) is far different to 1200 vs 2100. Additionally computer ratings are not human ratings while your two players are humans I presume.
There's no way with your example of 1200 and 2100 that a knight, or two pawns would be anywhere near sufficient for the 1200. Especially the two pawns, but also the knight.
The rule of thumb is that if the stronger player is winning you increase the handicap and if he is losing you decrease it. You'll quickly work it out.
In your case I would start with giving a queen.
