100 points higher: 66% score. e.g. 2 wins and 1 loss.
200 points higher: 75% score. e.g. 3 wins, 1 loss or 2 wins, 2 draws.
Can't remember it in anymore detail, other than to say that it's exponential, so the chances of scoring points get drastically smaller as the difference increases.
I have a question I have been interested in recently. Maybe this will be picked up by the more mathematically inclined in the group :)
What type of mathematical trend does rating (USCF) have with respect to skill. For example,in chemistry and on the pH scale, a pH of 1 is a 10x stronger acid than an acid with a pH of 2 (and is 100x stronger than a pH of 3, etc.).The trend is logarithmic.
Since skill is a nebulous term, maybe we could compare it to win ratio. For example, is a 2000 rated player 10x stronger than a 1900 rated player (say a 1900 rated player would beat a 2000 rated player only 10% of the time, and so on)?
I have heard that as you get higher in rating it becomes much, much, more difficult to increase that rating.