How does Strength of Play of a Personality (one of the options when you make/edit a Personality) relate to rating? I've noticed that approximately Playing Strength of 20 is 1000 rating. Then something like 40 Playing Strength is 1700.

Yet is it always liek this? Is there a linear relation? I've noticed that some of Chessmaster original Personalities have lower Strength, but they are higher rated.

No, there's no linear relation between Strength of Play and Rating. All of the options play a part in how the personality plays, and as a result, how it is rated.

You also need to keep in mind that ratings for most personalities change based on CPU speed -- for instance, "Liam" has a base rating of 1739, but on my computer his rating jumped to 1845...

Thanks. It makes sense.

That's also why some of the Personalities have a lower "base rating" comapred to what's their "real rating".