Improvement curve for good people

Given that someone eventually becomes good, how steep is their improvement curve? Is it possible to distinguish such people from noise early on in their trajectory?

An interesting case is when someone suddenly and magically appears online in very good condition, without displaying any bad traits (when they were still learning how to be good). I think Carl Shulman is a good example of this phenomenon. He suddenly appears around 2007 in pretty much his present-day condition.

I feel like some people have a really abrupt transition from "indistinguishable from bad person" to "output of good person" without going through "output of bad but promising person who will become good in a few years". Why is this?

This topic matters when thinking about "beating the market" on finding good people. It's also relevant when thinking about how often to check back on people you have previously dismissed.

Jonathan Blow is another interesting example. Could one have spotted promise in The Inner Product or his early games/demos? Or did it take until Braid (which made him super famous anyway, and would mean it wasn't possible to beat the market by identifying him early)?

I should more systematically look through examples to see the output/improvement curves for various people. Some interesting examples to look at: Wei Dai, Eliezer, Buck, Carl, Abram, Jessica Taylor, Grognor.