For example, in this post you seem to be setting the upper bound around 3x. But actually, it is trivial to be 3x more productive than average: (a) Don't browse the internet while at work; (b) Sit there and spend your time working on the actual problem, not ratholing on programmer fixations that have nothing to do with the end result. Done. Congratulations, you are now 3x, before any consideration is made of experience level or talent or smartness or unique instinct or whatever else.