In your chess example, there may be certain people that Magnus Carlsen should play chess against if he wants to improve. I don't know the specifics, but at lea

In your chess example, there may be certain people that Magnus Carlsen should play chess against if he wants to improve. I don't know the specifics, but at least logically it is possible that even though Carlsen has the best chess rating, there could be players who can consistently beat him due to how they match up with each other.