"Is it legitimate to assume that someone with 45 experience who is not yet "principal" level is incapable of making "principal"?" IMHO, without any other knowl

"Is it legitimate to assume that someone with 45 experience who is not yet "principal" level is incapable of making "principal"?" IMHO, without any other knowledge about the person, it's reasonable to calculate it happening with a lower probability than someone else. "Aren't there lots and lots of explanations for them not being at that level yet?" As my father used to say: "At some point, potential doesn't matter, it matters what you do with it". Why something happened is in some sense, irrelevant. They aren't at a level of competence you can hire them now. In practice, i don't give a rats ass about their age. I rate a 99 year old with 1 year experience the same way I rate a 30 year old with 1 year experience. But I definitely expect anybody with 20 years experience, be they 10, 20, 30, 100, 1000, or whatever, to be comparable to the other people with 20 years of experience. If they aren't, i can't hire them at that level. So then i have to decide if i want to hire them at a lower level, which means i have to compare them against lower levels, which involves calculating predicted future competence, often against the people with less years of experience, to see if i believe which will be a beter candidate. At that point, yes, what you've actually done matters, not why you did it. I can't know why you did it, i can only know what has actually happened. Honestly, i'd really like to understand why one would think the risk calculation of "conditional probability of guy who has been doing something for 45 years suddenly changing and becoming much better at it in 2 years" is somehow the same as "conditional probability of a guy who has been doing something for 1 year becoming much better at in 2 years". Because i just don't see it, and am truly struggling to understand why one would think these probabilities are equal, outside of "it seems politically incorrect to say they aren't" and we wish they weren't (As I said, I'm getting older too, so i wish they weren't myself :P) (Note experience means " in the job i want to hire him to do". So a 99 year old with 45 years experience as a math teacher is considered to have 0 years of experience as a software engineer, and i'd compare him against people with 0 years experience. So the guy with 45 years experience has been doing exactly the job i want to hire him to do for 45 years)