I tend to believe that it's not possible to reliably guess someone's rating if their rating is 400 points higher or lower than yours.
In other words if I saw a 1000 rated player play, it would probably look pretty good, and I'd have no idea why they're 1000. (I've seen lots of people overestimate new players for the same reason).
So since a 1000 level of skill is essentially invisible to me, it would be pretty interesting to know, quantitatively even, what the difference between 1000 and 1200 is. Or the difference between 800 and 1000.
@Ziryab you coach (or are at least around) a lot of kid beginners. Any insights re: what makes someone above or below 1000?
The average adult could easily reach a rating of 1000 with poor play.