As part of a recent (unrelated) thread to a question I asked, a perceptive colleague answered as quoted below:
"I'd hesitate to label anyone a "crackpot" without a precise definition of the term.
See John Baez Crackpot Index. This could be developed into a proper psychometric questionnaire, in which case I expect it to discriminate between crackpots and criterion groups of famous and average scientists, and particularly between cranks and those with new, challenging and unconventional but well-thought out ideas. If a well-standardised version of this with proper norms were available on the internet, it might well deter some of the nuisance crackpots."
My question is related to answering the position of 'are high-flying academic notables (past and present) extremely talented at what they do or did - or are they merely average 'crackpots' who are at the right place, at the right time?' I'm wondering, is there a fine-line between the concepts - or are they 'miles apart' - or can they be a mixture?